<?xml version="1.0" encoding="UTF-8"?><ns2:edgarSubmission xmlns:com="http://www.sec.gov/edgar/common" xmlns:ns2="http://www.sec.gov/edgar/ownership">
    <ns2:headerData>
        <ns2:submissionType>144</ns2:submissionType>
        <ns2:filerInfo>
            <ns2:filer>
                <ns2:filerCredentials>
                    <ns2:cik>0001239501</ns2:cik>
                    <ns2:ccc>XXXXXXXX</ns2:ccc>
                </ns2:filerCredentials>
            </ns2:filer>
            <ns2:liveTestFlag>LIVE</ns2:liveTestFlag>



        </ns2:filerInfo>
    </ns2:headerData>
    <ns2:formData>
        <ns2:issuerInfo>
            <ns2:issuerCik>0001447362</ns2:issuerCik>
            <ns2:issuerName>Castle Biosciences, Inc.</ns2:issuerName>
            <ns2:secFileNumber>001-38984</ns2:secFileNumber>
            <ns2:issuerAddress>
                <com:street1>505 S. Friendswood Drive</com:street1>
                <com:street2>Suite 401</com:street2>
                <com:city>Friendswood</com:city>
                <com:stateOrCountry>TX</com:stateOrCountry>
                <com:zipCode>77546</com:zipCode>
            </ns2:issuerAddress>
            <ns2:issuerContactPhone>1-866-788-9007</ns2:issuerContactPhone>
            <ns2:nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>Derek Maetzold</ns2:nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
            <ns2:relationshipsToIssuer>
                <ns2:relationshipToIssuer>Officer</ns2:relationshipToIssuer>
            </ns2:relationshipsToIssuer>
        </ns2:issuerInfo>
        <ns2:securitiesInformation>
            <ns2:securitiesClassTitle>Common</ns2:securitiesClassTitle>
            <ns2:brokerOrMarketmakerDetails>
                <ns2:name>Goldman Sachs &amp; Co. LLC</ns2:name>
                <ns2:address>
                    <com:street1>200 West Street</com:street1>
                    <com:city>New York</com:city>
                    <com:stateOrCountry>NY</com:stateOrCountry>
                    <com:zipCode>10282</com:zipCode>
                </ns2:address>
            </ns2:brokerOrMarketmakerDetails>
            <ns2:noOfUnitsSold>16932</ns2:noOfUnitsSold>
            <ns2:aggregateMarketValue>314935.2</ns2:aggregateMarketValue>
            <ns2:noOfUnitsOutstanding>28839188</ns2:noOfUnitsOutstanding>
            <ns2:approxSaleDate>04/08/2025</ns2:approxSaleDate>
            <ns2:securitiesExchangeName>NASD</ns2:securitiesExchangeName>
        </ns2:securitiesInformation>
        <ns2:securitiesToBeSold>
            <ns2:securitiesClassTitle>Common</ns2:securitiesClassTitle>
            <ns2:acquiredDate>10/29/2007</ns2:acquiredDate>
            <ns2:natureOfAcquisitionTransaction>Acquired as gift</ns2:natureOfAcquisitionTransaction>
            <ns2:nameOfPersonfromWhomAcquired>Derek Maetzold</ns2:nameOfPersonfromWhomAcquired>
            <ns2:isGiftTransaction>Y</ns2:isGiftTransaction>
            <ns2:donarAcquiredDate>10/29/2007</ns2:donarAcquiredDate>
            <ns2:amountOfSecuritiesAcquired>6051</ns2:amountOfSecuritiesAcquired>
            <ns2:paymentDate>10/29/2007</ns2:paymentDate>
            <ns2:natureOfPayment>None</ns2:natureOfPayment>
        </ns2:securitiesToBeSold>
        <ns2:securitiesToBeSold>
            <ns2:securitiesClassTitle>Common</ns2:securitiesClassTitle>
            <ns2:acquiredDate>10/29/2007</ns2:acquiredDate>
            <ns2:natureOfAcquisitionTransaction>Acquired as gift</ns2:natureOfAcquisitionTransaction>
            <ns2:nameOfPersonfromWhomAcquired>Derek Maetzold</ns2:nameOfPersonfromWhomAcquired>
            <ns2:isGiftTransaction>Y</ns2:isGiftTransaction>
            <ns2:donarAcquiredDate>10/29/2007</ns2:donarAcquiredDate>
            <ns2:amountOfSecuritiesAcquired>5193</ns2:amountOfSecuritiesAcquired>
            <ns2:paymentDate>10/29/2007</ns2:paymentDate>
            <ns2:natureOfPayment>None</ns2:natureOfPayment>
        </ns2:securitiesToBeSold>
        <ns2:securitiesToBeSold>
            <ns2:securitiesClassTitle>Common</ns2:securitiesClassTitle>
            <ns2:acquiredDate>10/29/2007</ns2:acquiredDate>
            <ns2:natureOfAcquisitionTransaction>Acquired as gift</ns2:natureOfAcquisitionTransaction>
            <ns2:nameOfPersonfromWhomAcquired>Derek Maetzold</ns2:nameOfPersonfromWhomAcquired>
            <ns2:isGiftTransaction>Y</ns2:isGiftTransaction>
            <ns2:donarAcquiredDate>10/29/2007</ns2:donarAcquiredDate>
            <ns2:amountOfSecuritiesAcquired>495</ns2:amountOfSecuritiesAcquired>
            <ns2:paymentDate>10/29/2007</ns2:paymentDate>
            <ns2:natureOfPayment>None</ns2:natureOfPayment>
        </ns2:securitiesToBeSold>
        <ns2:securitiesToBeSold>
            <ns2:securitiesClassTitle>Common</ns2:securitiesClassTitle>
            <ns2:acquiredDate>10/29/2007</ns2:acquiredDate>
            <ns2:natureOfAcquisitionTransaction>Acquired as gift</ns2:natureOfAcquisitionTransaction>
            <ns2:nameOfPersonfromWhomAcquired>Derek Maetzold</ns2:nameOfPersonfromWhomAcquired>
            <ns2:isGiftTransaction>Y</ns2:isGiftTransaction>
            <ns2:donarAcquiredDate>10/29/2007</ns2:donarAcquiredDate>
            <ns2:amountOfSecuritiesAcquired>495</ns2:amountOfSecuritiesAcquired>
            <ns2:paymentDate>10/29/2007</ns2:paymentDate>
            <ns2:natureOfPayment>None</ns2:natureOfPayment>
        </ns2:securitiesToBeSold>
        <ns2:securitiesToBeSold>
            <ns2:securitiesClassTitle>Common</ns2:securitiesClassTitle>
            <ns2:acquiredDate>10/29/2007</ns2:acquiredDate>
            <ns2:natureOfAcquisitionTransaction>Acquired as gift</ns2:natureOfAcquisitionTransaction>
            <ns2:nameOfPersonfromWhomAcquired>Derek Maetzold</ns2:nameOfPersonfromWhomAcquired>
            <ns2:isGiftTransaction>Y</ns2:isGiftTransaction>
            <ns2:donarAcquiredDate>10/29/2007</ns2:donarAcquiredDate>
            <ns2:amountOfSecuritiesAcquired>495</ns2:amountOfSecuritiesAcquired>
            <ns2:paymentDate>10/29/2007</ns2:paymentDate>
            <ns2:natureOfPayment>None</ns2:natureOfPayment>
        </ns2:securitiesToBeSold>
        <ns2:securitiesToBeSold>
            <ns2:securitiesClassTitle>Common</ns2:securitiesClassTitle>
            <ns2:acquiredDate>10/29/2007</ns2:acquiredDate>
            <ns2:natureOfAcquisitionTransaction>Acquired as gift</ns2:natureOfAcquisitionTransaction>
            <ns2:nameOfPersonfromWhomAcquired>Derek Maetzold</ns2:nameOfPersonfromWhomAcquired>
            <ns2:isGiftTransaction>Y</ns2:isGiftTransaction>
            <ns2:donarAcquiredDate>10/29/2007</ns2:donarAcquiredDate>
            <ns2:amountOfSecuritiesAcquired>495</ns2:amountOfSecuritiesAcquired>
            <ns2:paymentDate>10/29/2007</ns2:paymentDate>
            <ns2:natureOfPayment>None</ns2:natureOfPayment>
        </ns2:securitiesToBeSold>
        <ns2:securitiesToBeSold>
            <ns2:securitiesClassTitle>Common</ns2:securitiesClassTitle>
            <ns2:acquiredDate>08/09/2024</ns2:acquiredDate>
            <ns2:natureOfAcquisitionTransaction>Acquired as compensation -- Performance Awards</ns2:natureOfAcquisitionTransaction>
            <ns2:nameOfPersonfromWhomAcquired>Issuer</ns2:nameOfPersonfromWhomAcquired>
            <ns2:isGiftTransaction>N</ns2:isGiftTransaction>
            <ns2:amountOfSecuritiesAcquired>3708</ns2:amountOfSecuritiesAcquired>
            <ns2:paymentDate>08/09/2024</ns2:paymentDate>
            <ns2:natureOfPayment>Compensation</ns2:natureOfPayment>
        </ns2:securitiesToBeSold>
        <ns2:nothingToReportFlagOnSecuritiesSoldInPast3Months>N</ns2:nothingToReportFlagOnSecuritiesSoldInPast3Months>
        <ns2:securitiesSoldInPast3Months>
            <ns2:sellerDetails>
                <ns2:name>Derek Maetzold</ns2:name>
                <ns2:address>
                    <com:street1>505 S. Friendswood Drive</com:street1>
                    <com:street2>Suite 401</com:street2>
                    <com:city>Friendswood</com:city>
                    <com:stateOrCountry>TX</com:stateOrCountry>
                    <com:zipCode>77546</com:zipCode>
                </ns2:address>
            </ns2:sellerDetails>
            <ns2:securitiesClassTitle>Common</ns2:securitiesClassTitle>
            <ns2:saleDate>03/07/2025</ns2:saleDate>
            <ns2:amountOfSecuritiesSold>21403</ns2:amountOfSecuritiesSold>
            <ns2:grossProceeds>428432.41</ns2:grossProceeds>
        </ns2:securitiesSoldInPast3Months>
        <ns2:securitiesSoldInPast3Months>
            <ns2:sellerDetails>
                <ns2:name>The Maetzold Descendants 2020 Trust dtd 12/4/2020</ns2:name>
                <ns2:address>
                    <com:street1>505 S. Friendswood Drive</com:street1>
                    <com:street2>Suite 401</com:street2>
                    <com:city>Friendswood</com:city>
                    <com:stateOrCountry>TX</com:stateOrCountry>
                    <com:zipCode>77546</com:zipCode>
                </ns2:address>
            </ns2:sellerDetails>
            <ns2:securitiesClassTitle>Common</ns2:securitiesClassTitle>
            <ns2:saleDate>03/04/2025</ns2:saleDate>
            <ns2:amountOfSecuritiesSold>2022</ns2:amountOfSecuritiesSold>
            <ns2:grossProceeds>42174.27</ns2:grossProceeds>
        </ns2:securitiesSoldInPast3Months>
        <ns2:securitiesSoldInPast3Months>
            <ns2:sellerDetails>
                <ns2:name>The Maetzold 2018 Remainder Trust f/b/o John Derek Maetzold</ns2:name>
                <ns2:address>
                    <com:street1>505 S. Friendswood Drive</com:street1>
                    <com:street2>Suite 401</com:street2>
                    <com:city>Friendswood</com:city>
                    <com:stateOrCountry>TX</com:stateOrCountry>
                    <com:zipCode>77546</com:zipCode>
                </ns2:address>
            </ns2:sellerDetails>
            <ns2:securitiesClassTitle>Common</ns2:securitiesClassTitle>
            <ns2:saleDate>03/04/2025</ns2:saleDate>
            <ns2:amountOfSecuritiesSold>169</ns2:amountOfSecuritiesSold>
            <ns2:grossProceeds>3524.95</ns2:grossProceeds>
        </ns2:securitiesSoldInPast3Months>
        <ns2:securitiesSoldInPast3Months>
            <ns2:sellerDetails>
                <ns2:name>The Maetzold 2018 Remainder Trust f/b/o Peter Douglas Maetzold</ns2:name>
                <ns2:address>
                    <com:street1>505 S. Friendswood Drive</com:street1>
                    <com:street2>Suite 401</com:street2>
                    <com:city>Friendswood</com:city>
                    <com:stateOrCountry>TX</com:stateOrCountry>
                    <com:zipCode>77546</com:zipCode>
                </ns2:address>
            </ns2:sellerDetails>
            <ns2:securitiesClassTitle>Common</ns2:securitiesClassTitle>
            <ns2:saleDate>03/04/2025</ns2:saleDate>
            <ns2:amountOfSecuritiesSold>169</ns2:amountOfSecuritiesSold>
            <ns2:grossProceeds>3524.95</ns2:grossProceeds>
        </ns2:securitiesSoldInPast3Months>
        <ns2:securitiesSoldInPast3Months>
            <ns2:sellerDetails>
                <ns2:name>Derek Maetzold</ns2:name>
                <ns2:address>
                    <com:street1>505 S. Friendswood Drive</com:street1>
                    <com:street2>Suite 401</com:street2>
                    <com:city>Friendswood</com:city>
                    <com:stateOrCountry>TX</com:stateOrCountry>
                    <com:zipCode>77546</com:zipCode>
                </ns2:address>
            </ns2:sellerDetails>
            <ns2:securitiesClassTitle>Common</ns2:securitiesClassTitle>
            <ns2:saleDate>03/04/2025</ns2:saleDate>
            <ns2:amountOfSecuritiesSold>1247</ns2:amountOfSecuritiesSold>
            <ns2:grossProceeds>26009.55</ns2:grossProceeds>
        </ns2:securitiesSoldInPast3Months>
        <ns2:securitiesSoldInPast3Months>
            <ns2:sellerDetails>
                <ns2:name>Derek Maetzold 2020 Irrevocable Trust dtd 12/04/2020</ns2:name>
                <ns2:address>
                    <com:street1>505 S. Friendswood Drive</com:street1>
                    <com:street2>Suite 401</com:street2>
                    <com:city>Friendswood</com:city>
                    <com:stateOrCountry>TX</com:stateOrCountry>
                    <com:zipCode>77546</com:zipCode>
                </ns2:address>
            </ns2:sellerDetails>
            <ns2:securitiesClassTitle>Common</ns2:securitiesClassTitle>
            <ns2:saleDate>03/04/2025</ns2:saleDate>
            <ns2:amountOfSecuritiesSold>1739</ns2:amountOfSecuritiesSold>
            <ns2:grossProceeds>36271.54</ns2:grossProceeds>
        </ns2:securitiesSoldInPast3Months>
        <ns2:securitiesSoldInPast3Months>
            <ns2:sellerDetails>
                <ns2:name>The Maetzold 2018 Remainder Trust f/b/o Hannah Elizabeth Maetzold</ns2:name>
                <ns2:address>
                    <com:street1>505 S. Friendswood Drive</com:street1>
                    <com:street2>Suite 401</com:street2>
                    <com:city>Friendswood</com:city>
                    <com:stateOrCountry>TX</com:stateOrCountry>
                    <com:zipCode>77546</com:zipCode>
                </ns2:address>
            </ns2:sellerDetails>
            <ns2:securitiesClassTitle>Common</ns2:securitiesClassTitle>
            <ns2:saleDate>03/04/2025</ns2:saleDate>
            <ns2:amountOfSecuritiesSold>169</ns2:amountOfSecuritiesSold>
            <ns2:grossProceeds>3524.95</ns2:grossProceeds>
        </ns2:securitiesSoldInPast3Months>
        <ns2:securitiesSoldInPast3Months>
            <ns2:sellerDetails>
                <ns2:name>The Maetzold 2018 Remainder Trust f/b/o Emily Carol Kirk</ns2:name>
                <ns2:address>
                    <com:street1>505 S. Friendswood Drive</com:street1>
                    <com:street2>Suite 401</com:street2>
                    <com:city>Friendswood</com:city>
                    <com:stateOrCountry>TX</com:stateOrCountry>
                    <com:zipCode>77546</com:zipCode>
                </ns2:address>
            </ns2:sellerDetails>
            <ns2:securitiesClassTitle>Common</ns2:securitiesClassTitle>
            <ns2:saleDate>03/04/2025</ns2:saleDate>
            <ns2:amountOfSecuritiesSold>172</ns2:amountOfSecuritiesSold>
            <ns2:grossProceeds>3587.52</ns2:grossProceeds>
        </ns2:securitiesSoldInPast3Months>
        <ns2:securitiesSoldInPast3Months>
            <ns2:sellerDetails>
                <ns2:name>The Maetzold Descendants 2020 Trust dtd 12/4/2020</ns2:name>
                <ns2:address>
                    <com:street1>505 S. Friendswood Drive</com:street1>
                    <com:street2>Suite 401</com:street2>
                    <com:city>Friendswood</com:city>
                    <com:stateOrCountry>TX</com:stateOrCountry>
                    <com:zipCode>77546</com:zipCode>
                </ns2:address>
            </ns2:sellerDetails>
            <ns2:securitiesClassTitle>Common</ns2:securitiesClassTitle>
            <ns2:saleDate>03/26/2025</ns2:saleDate>
            <ns2:amountOfSecuritiesSold>2017</ns2:amountOfSecuritiesSold>
            <ns2:grossProceeds>40943.28</ns2:grossProceeds>
        </ns2:securitiesSoldInPast3Months>
        <ns2:securitiesSoldInPast3Months>
            <ns2:sellerDetails>
                <ns2:name>The Maetzold 2018 Remainder Trust f/b/o John Derek Maetzold</ns2:name>
                <ns2:address>
                    <com:street1>505 S. Friendswood Drive</com:street1>
                    <com:street2>Suite 401</com:street2>
                    <com:city>Friendswood</com:city>
                    <com:stateOrCountry>TX</com:stateOrCountry>
                    <com:zipCode>77546</com:zipCode>
                </ns2:address>
            </ns2:sellerDetails>
            <ns2:securitiesClassTitle>Common</ns2:securitiesClassTitle>
            <ns2:saleDate>03/26/2025</ns2:saleDate>
            <ns2:amountOfSecuritiesSold>165</ns2:amountOfSecuritiesSold>
            <ns2:grossProceeds>3349.35</ns2:grossProceeds>
        </ns2:securitiesSoldInPast3Months>
        <ns2:securitiesSoldInPast3Months>
            <ns2:sellerDetails>
                <ns2:name>The Maetzold 2018 Remainder Trust f/b/o Peter Douglas Maetzold</ns2:name>
                <ns2:address>
                    <com:street1>505 S. Friendswood Drive</com:street1>
                    <com:street2>Suite 401</com:street2>
                    <com:city>Friendswood</com:city>
                    <com:stateOrCountry>TX</com:stateOrCountry>
                    <com:zipCode>77546</com:zipCode>
                </ns2:address>
            </ns2:sellerDetails>
            <ns2:securitiesClassTitle>Common</ns2:securitiesClassTitle>
            <ns2:saleDate>03/26/2025</ns2:saleDate>
            <ns2:amountOfSecuritiesSold>165</ns2:amountOfSecuritiesSold>
            <ns2:grossProceeds>3349.35</ns2:grossProceeds>
        </ns2:securitiesSoldInPast3Months>
        <ns2:securitiesSoldInPast3Months>
            <ns2:sellerDetails>
                <ns2:name>Derek Maetzold</ns2:name>
                <ns2:address>
                    <com:street1>505 S. Friendswood Drive</com:street1>
                    <com:street2>Suite 401</com:street2>
                    <com:city>Friendswood</com:city>
                    <com:stateOrCountry>TX</com:stateOrCountry>
                    <com:zipCode>77546</com:zipCode>
                </ns2:address>
            </ns2:sellerDetails>
            <ns2:securitiesClassTitle>Common</ns2:securitiesClassTitle>
            <ns2:saleDate>03/26/2025</ns2:saleDate>
            <ns2:amountOfSecuritiesSold>1236</ns2:amountOfSecuritiesSold>
            <ns2:grossProceeds>25089.69</ns2:grossProceeds>
        </ns2:securitiesSoldInPast3Months>
        <ns2:securitiesSoldInPast3Months>
            <ns2:sellerDetails>
                <ns2:name>Derek Maetzold 2020 Irrevocable Trust dtd 12/04/2020</ns2:name>
                <ns2:address>
                    <com:street1>505 S. Friendswood Drive</com:street1>
                    <com:street2>Suite 401</com:street2>
                    <com:city>Friendswood</com:city>
                    <com:stateOrCountry>TX</com:stateOrCountry>
                    <com:zipCode>77546</com:zipCode>
                </ns2:address>
            </ns2:sellerDetails>
            <ns2:securitiesClassTitle>Common</ns2:securitiesClassTitle>
            <ns2:saleDate>03/26/2025</ns2:saleDate>
            <ns2:amountOfSecuritiesSold>1731</ns2:amountOfSecuritiesSold>
            <ns2:grossProceeds>35137.74</ns2:grossProceeds>
        </ns2:securitiesSoldInPast3Months>
        <ns2:securitiesSoldInPast3Months>
            <ns2:sellerDetails>
                <ns2:name>The Maetzold 2018 Remainder Trust f/b/o Hannah Elizabeth Maetzold</ns2:name>
                <ns2:address>
                    <com:street1>505 S. Friendswood Drive</com:street1>
                    <com:street2>Suite 401</com:street2>
                    <com:city>Friendswood</com:city>
                    <com:stateOrCountry>TX</com:stateOrCountry>
                    <com:zipCode>77546</com:zipCode>
                </ns2:address>
            </ns2:sellerDetails>
            <ns2:securitiesClassTitle>Common</ns2:securitiesClassTitle>
            <ns2:saleDate>03/26/2025</ns2:saleDate>
            <ns2:amountOfSecuritiesSold>165</ns2:amountOfSecuritiesSold>
            <ns2:grossProceeds>3349.35</ns2:grossProceeds>
        </ns2:securitiesSoldInPast3Months>
        <ns2:securitiesSoldInPast3Months>
            <ns2:sellerDetails>
                <ns2:name>The Maetzold 2018 Remainder Trust f/b/o Emily Carol Kirk</ns2:name>
                <ns2:address>
                    <com:street1>505 S. Friendswood Drive</com:street1>
                    <com:street2>Suite 401</com:street2>
                    <com:city>Friendswood</com:city>
                    <com:stateOrCountry>TX</com:stateOrCountry>
                    <com:zipCode>77546</com:zipCode>
                </ns2:address>
            </ns2:sellerDetails>
            <ns2:securitiesClassTitle>Common</ns2:securitiesClassTitle>
            <ns2:saleDate>03/26/2025</ns2:saleDate>
            <ns2:amountOfSecuritiesSold>165</ns2:amountOfSecuritiesSold>
            <ns2:grossProceeds>3349.35</ns2:grossProceeds>
        </ns2:securitiesSoldInPast3Months>
        <ns2:securitiesSoldInPast3Months>
            <ns2:sellerDetails>
                <ns2:name>The Maetzold Descendants 2020 Trust dtd 12/4/2020</ns2:name>
                <ns2:address>
                    <com:street1>505 S. Friendswood Drive</com:street1>
                    <com:street2>Suite 401</com:street2>
                    <com:city>Friendswood</com:city>
                    <com:stateOrCountry>TX</com:stateOrCountry>
                    <com:zipCode>77546</com:zipCode>
                </ns2:address>
            </ns2:sellerDetails>
            <ns2:securitiesClassTitle>Common</ns2:securitiesClassTitle>
            <ns2:saleDate>03/07/2025</ns2:saleDate>
            <ns2:amountOfSecuritiesSold>2017</ns2:amountOfSecuritiesSold>
            <ns2:grossProceeds>41331.76</ns2:grossProceeds>
        </ns2:securitiesSoldInPast3Months>
        <ns2:securitiesSoldInPast3Months>
            <ns2:sellerDetails>
                <ns2:name>The Maetzold 2018 Remainder Trust f/b/o John Derek Maetzold</ns2:name>
                <ns2:address>
                    <com:street1>505 S. Friendswood Drive</com:street1>
                    <com:street2>Suite 401</com:street2>
                    <com:city>Friendswood</com:city>
                    <com:stateOrCountry>TX</com:stateOrCountry>
                    <com:zipCode>77546</com:zipCode>
                </ns2:address>
            </ns2:sellerDetails>
            <ns2:securitiesClassTitle>Common</ns2:securitiesClassTitle>
            <ns2:saleDate>03/07/2025</ns2:saleDate>
            <ns2:amountOfSecuritiesSold>165</ns2:amountOfSecuritiesSold>
            <ns2:grossProceeds>3381.13</ns2:grossProceeds>
        </ns2:securitiesSoldInPast3Months>
        <ns2:securitiesSoldInPast3Months>
            <ns2:sellerDetails>
                <ns2:name>The Maetzold 2018 Remainder Trust f/b/o Peter Douglas Maetzold</ns2:name>
                <ns2:address>
                    <com:street1>505 S. Friendswood Drive</com:street1>
                    <com:street2>Suite 401</com:street2>
                    <com:city>Friendswood</com:city>
                    <com:stateOrCountry>TX</com:stateOrCountry>
                    <com:zipCode>77546</com:zipCode>
                </ns2:address>
            </ns2:sellerDetails>
            <ns2:securitiesClassTitle>Common</ns2:securitiesClassTitle>
            <ns2:saleDate>03/07/2025</ns2:saleDate>
            <ns2:amountOfSecuritiesSold>165</ns2:amountOfSecuritiesSold>
            <ns2:grossProceeds>3381.13</ns2:grossProceeds>
        </ns2:securitiesSoldInPast3Months>
        <ns2:securitiesSoldInPast3Months>
            <ns2:sellerDetails>
                <ns2:name>Derek Maetzold</ns2:name>
                <ns2:address>
                    <com:street1>505 S. Friendswood Drive</com:street1>
                    <com:street2>Suite 401</com:street2>
                    <com:city>Friendswood</com:city>
                    <com:stateOrCountry>TX</com:stateOrCountry>
                    <com:zipCode>77546</com:zipCode>
                </ns2:address>
            </ns2:sellerDetails>
            <ns2:securitiesClassTitle>Common</ns2:securitiesClassTitle>
            <ns2:saleDate>03/07/2025</ns2:saleDate>
            <ns2:amountOfSecuritiesSold>1236</ns2:amountOfSecuritiesSold>
            <ns2:grossProceeds>25327.74</ns2:grossProceeds>
        </ns2:securitiesSoldInPast3Months>
        <ns2:securitiesSoldInPast3Months>
            <ns2:sellerDetails>
                <ns2:name>Derek Maetzold 2020 Irrevocable Trust dtd 12/04/2020</ns2:name>
                <ns2:address>
                    <com:street1>505 S. Friendswood Drive</com:street1>
                    <com:street2>Suite 401</com:street2>
                    <com:city>Friendswood</com:city>
                    <com:stateOrCountry>TX</com:stateOrCountry>
                    <com:zipCode>77546</com:zipCode>
                </ns2:address>
            </ns2:sellerDetails>
            <ns2:securitiesClassTitle>Common</ns2:securitiesClassTitle>
            <ns2:saleDate>03/07/2025</ns2:saleDate>
            <ns2:amountOfSecuritiesSold>1731</ns2:amountOfSecuritiesSold>
            <ns2:grossProceeds>35471.13</ns2:grossProceeds>
        </ns2:securitiesSoldInPast3Months>
        <ns2:securitiesSoldInPast3Months>
            <ns2:sellerDetails>
                <ns2:name>The Maetzold 2018 Remainder Trust f/b/o Hannah Elizabeth Maetzold</ns2:name>
                <ns2:address>
                    <com:street1>505 S. Friendswood Drive</com:street1>
                    <com:street2>Suite 401</com:street2>
                    <com:city>Friendswood</com:city>
                    <com:stateOrCountry>TX</com:stateOrCountry>
                    <com:zipCode>77546</com:zipCode>
                </ns2:address>
            </ns2:sellerDetails>
            <ns2:securitiesClassTitle>Common</ns2:securitiesClassTitle>
            <ns2:saleDate>03/07/2025</ns2:saleDate>
            <ns2:amountOfSecuritiesSold>165</ns2:amountOfSecuritiesSold>
            <ns2:grossProceeds>3381.13</ns2:grossProceeds>
        </ns2:securitiesSoldInPast3Months>
        <ns2:securitiesSoldInPast3Months>
            <ns2:sellerDetails>
                <ns2:name>The Maetzold 2018 Remainder Trust f/b/o Emily Carol Kirk</ns2:name>
                <ns2:address>
                    <com:street1>505 S. Friendswood Drive</com:street1>
                    <com:street2>Suite 401</com:street2>
                    <com:city>Friendswood</com:city>
                    <com:stateOrCountry>TX</com:stateOrCountry>
                    <com:zipCode>77546</com:zipCode>
                </ns2:address>
            </ns2:sellerDetails>
            <ns2:securitiesClassTitle>Common</ns2:securitiesClassTitle>
            <ns2:saleDate>03/07/2025</ns2:saleDate>
            <ns2:amountOfSecuritiesSold>165</ns2:amountOfSecuritiesSold>
            <ns2:grossProceeds>3381.13</ns2:grossProceeds>
        </ns2:securitiesSoldInPast3Months>
        <ns2:securitiesSoldInPast3Months>
            <ns2:sellerDetails>
                <ns2:name>Derek Maetzold</ns2:name>
                <ns2:address>
                    <com:street1>505 S. Friendswood Drive</com:street1>
                    <com:street2>Suite 401</com:street2>
                    <com:city>Friendswood</com:city>
                    <com:stateOrCountry>TX</com:stateOrCountry>
                    <com:zipCode>77546</com:zipCode>
                </ns2:address>
            </ns2:sellerDetails>
            <ns2:securitiesClassTitle>Common</ns2:securitiesClassTitle>
            <ns2:saleDate>03/10/2025</ns2:saleDate>
            <ns2:amountOfSecuritiesSold>2130</ns2:amountOfSecuritiesSold>
            <ns2:grossProceeds>41573.98</ns2:grossProceeds>
        </ns2:securitiesSoldInPast3Months>
        <ns2:securitiesSoldInPast3Months>
            <ns2:sellerDetails>
                <ns2:name>The Maetzold 2018 Remainder Trust f/b/o Peter Douglas Maetzold</ns2:name>
                <ns2:address>
                    <com:street1>505 S. Friendswood Drive</com:street1>
                    <com:street2>Suite 401</com:street2>
                    <com:city>Friendswood</com:city>
                    <com:stateOrCountry>TX</com:stateOrCountry>
                    <com:zipCode>77546</com:zipCode>
                </ns2:address>
            </ns2:sellerDetails>
            <ns2:securitiesClassTitle>Common</ns2:securitiesClassTitle>
            <ns2:saleDate>01/13/2025</ns2:saleDate>
            <ns2:amountOfSecuritiesSold>150</ns2:amountOfSecuritiesSold>
            <ns2:grossProceeds>4204.41</ns2:grossProceeds>
        </ns2:securitiesSoldInPast3Months>
        <ns2:securitiesSoldInPast3Months>
            <ns2:sellerDetails>
                <ns2:name>Derek Maetzold</ns2:name>
                <ns2:address>
                    <com:street1>505 S. Friendswood Drive</com:street1>
                    <com:street2>Suite 401</com:street2>
                    <com:city>Friendswood</com:city>
                    <com:stateOrCountry>TX</com:stateOrCountry>
                    <com:zipCode>77546</com:zipCode>
                </ns2:address>
            </ns2:sellerDetails>
            <ns2:securitiesClassTitle>Common</ns2:securitiesClassTitle>
            <ns2:saleDate>01/13/2025</ns2:saleDate>
            <ns2:amountOfSecuritiesSold>986</ns2:amountOfSecuritiesSold>
            <ns2:grossProceeds>27636.99</ns2:grossProceeds>
        </ns2:securitiesSoldInPast3Months>
        <ns2:securitiesSoldInPast3Months>
            <ns2:sellerDetails>
                <ns2:name>The Maetzold 2018 Remainder Trust f/b/o Hannah Elizabeth Maetzold</ns2:name>
                <ns2:address>
                    <com:street1>505 S. Friendswood Drive</com:street1>
                    <com:street2>Suite 401</com:street2>
                    <com:city>Friendswood</com:city>
                    <com:stateOrCountry>TX</com:stateOrCountry>
                    <com:zipCode>77546</com:zipCode>
                </ns2:address>
            </ns2:sellerDetails>
            <ns2:securitiesClassTitle>Common</ns2:securitiesClassTitle>
            <ns2:saleDate>01/13/2025</ns2:saleDate>
            <ns2:amountOfSecuritiesSold>150</ns2:amountOfSecuritiesSold>
            <ns2:grossProceeds>4204.41</ns2:grossProceeds>
        </ns2:securitiesSoldInPast3Months>
        <ns2:securitiesSoldInPast3Months>
            <ns2:sellerDetails>
                <ns2:name>The Maetzold 2018 Remainder Trust f/b/o Emily Carol Kirk</ns2:name>
                <ns2:address>
                    <com:street1>505 S. Friendswood Drive</com:street1>
                    <com:street2>Suite 401</com:street2>
                    <com:city>Friendswood</com:city>
                    <com:stateOrCountry>TX</com:stateOrCountry>
                    <com:zipCode>77546</com:zipCode>
                </ns2:address>
            </ns2:sellerDetails>
            <ns2:securitiesClassTitle>Common</ns2:securitiesClassTitle>
            <ns2:saleDate>01/13/2025</ns2:saleDate>
            <ns2:amountOfSecuritiesSold>150</ns2:amountOfSecuritiesSold>
            <ns2:grossProceeds>4204.41</ns2:grossProceeds>
        </ns2:securitiesSoldInPast3Months>
        <ns2:remarks>Total number of shares to be sold includes: 3,708 shares by Derek Maetzold, 5,193 shares by DM 2020 Irrev Tr, 6051 shares by Maetzold Descendants 2020 Tr, 495 shares by Hannah Maetzold Irrev. Trust, 495 shares by Peter Maetzold Irrev. Trust, 495 shares by Emily Maetzold Irrev. Trust, 495 shares by John Maetzold Irrev. Trust. The sales of shares set forth herein are made in connection with a selling plan dated 11/11/2024 that is intended to comply with Rule 10b5-1(c).</ns2:remarks>
        <ns2:noticeSignature>
            <ns2:noticeDate>04/08/2025</ns2:noticeDate>
            <ns2:planAdoptionDates>
                <ns2:planAdoptionDate>11/11/2024</ns2:planAdoptionDate>
            </ns2:planAdoptionDates>
            <ns2:signature>Goldman Sachs &amp; Co. LLC on behalf of Derek Maetzold</ns2:signature>
        </ns2:noticeSignature>
    </ns2:formData>
</ns2:edgarSubmission>
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144
0001239501
XXXXXXXX
LIVE
0001447362
Castle Biosciences, Inc.
001-38984
505 S. Friendswood Drive
Suite 401
Friendswood
TX
77546
1-866-788-9007
Derek Maetzold
Officer
Common
Goldman Sachs & Co. LLC
200 West Street
New York
NY
10282
16932
314935.2
28839188
04/08/2025
NASD
Common
10/29/2007
Acquired as gift
Derek Maetzold
Y
10/29/2007
6051
10/29/2007
None
Common
10/29/2007
Acquired as gift
Derek Maetzold
Y
10/29/2007
5193
10/29/2007
None
Common
10/29/2007
Acquired as gift
Derek Maetzold
Y
10/29/2007
495
10/29/2007
None
Common
10/29/2007
Acquired as gift
Derek Maetzold
Y
10/29/2007
495
10/29/2007
None
Common
10/29/2007
Acquired as gift
Derek Maetzold
Y
10/29/2007
495
10/29/2007
None
Common
10/29/2007
Acquired as gift
Derek Maetzold
Y
10/29/2007
495
10/29/2007
None
Common
08/09/2024
Acquired as compensation -- Performance Awards
Issuer
N
3708
08/09/2024
Compensation
N
Derek Maetzold
505 S. Friendswood Drive
Suite 401
Friendswood
TX
77546
Common
03/07/2025
21403
428432.41
The Maetzold Descendants 2020 Trust dtd 12/4/2020
505 S. Friendswood Drive
Suite 401
Friendswood
TX
77546
Common
03/04/2025
2022
42174.27
The Maetzold 2018 Remainder Trust f/b/o John Derek Maetzold
505 S. Friendswood Drive
Suite 401
Friendswood
TX
77546
Common
03/04/2025
169
3524.95
The Maetzold 2018 Remainder Trust f/b/o Peter Douglas Maetzold
505 S. Friendswood Drive
Suite 401
Friendswood
TX
77546
Common
03/04/2025
169
3524.95
Derek Maetzold
505 S. Friendswood Drive
Suite 401
Friendswood
TX
77546
Common
03/04/2025
1247
26009.55
Derek Maetzold 2020 Irrevocable Trust dtd 12/04/2020
505 S. Friendswood Drive
Suite 401
Friendswood
TX
77546
Common
03/04/2025
1739
36271.54
The Maetzold 2018 Remainder Trust f/b/o Hannah Elizabeth Maetzold
505 S. Friendswood Drive
Suite 401
Friendswood
TX
77546
Common
03/04/2025
169
3524.95
The Maetzold 2018 Remainder Trust f/b/o Emily Carol Kirk
505 S. Friendswood Drive
Suite 401
Friendswood
TX
77546
Common
03/04/2025
172
3587.52
The Maetzold Descendants 2020 Trust dtd 12/4/2020
505 S. Friendswood Drive
Suite 401
Friendswood
TX
77546
Common
03/26/2025
2017
40943.28
The Maetzold 2018 Remainder Trust f/b/o John Derek Maetzold
505 S. Friendswood Drive
Suite 401
Friendswood
TX
77546
Common
03/26/2025
165
3349.35
The Maetzold 2018 Remainder Trust f/b/o Peter Douglas Maetzold
505 S. Friendswood Drive
Suite 401
Friendswood
TX
77546
Common
03/26/2025
165
3349.35
Derek Maetzold
505 S. Friendswood Drive
Suite 401
Friendswood
TX
77546
Common
03/26/2025
1236
25089.69
Derek Maetzold 2020 Irrevocable Trust dtd 12/04/2020
505 S. Friendswood Drive
Suite 401
Friendswood
TX
77546
Common
03/26/2025
1731
35137.74
The Maetzold 2018 Remainder Trust f/b/o Hannah Elizabeth Maetzold
505 S. Friendswood Drive
Suite 401
Friendswood
TX
77546
Common
03/26/2025
165
3349.35
The Maetzold 2018 Remainder Trust f/b/o Emily Carol Kirk
505 S. Friendswood Drive
Suite 401
Friendswood
TX
77546
Common
03/26/2025
165
3349.35
The Maetzold Descendants 2020 Trust dtd 12/4/2020
505 S. Friendswood Drive
Suite 401
Friendswood
TX
77546
Common
03/07/2025
2017
41331.76
The Maetzold 2018 Remainder Trust f/b/o John Derek Maetzold
505 S. Friendswood Drive
Suite 401
Friendswood
TX
77546
Common
03/07/2025
165
3381.13
The Maetzold 2018 Remainder Trust f/b/o Peter Douglas Maetzold
505 S. Friendswood Drive
Suite 401
Friendswood
TX
77546
Common
03/07/2025
165
3381.13
Derek Maetzold
505 S. Friendswood Drive
Suite 401
Friendswood
TX
77546
Common
03/07/2025
1236
25327.74
Derek Maetzold 2020 Irrevocable Trust dtd 12/04/2020
505 S. Friendswood Drive
Suite 401
Friendswood
TX
77546
Common
03/07/2025
1731
35471.13
The Maetzold 2018 Remainder Trust f/b/o Hannah Elizabeth Maetzold
505 S. Friendswood Drive
Suite 401
Friendswood
TX
77546
Common
03/07/2025
165
3381.13
The Maetzold 2018 Remainder Trust f/b/o Emily Carol Kirk
505 S. Friendswood Drive
Suite 401
Friendswood
TX
77546
Common
03/07/2025
165
3381.13
Derek Maetzold
505 S. Friendswood Drive
Suite 401
Friendswood
TX
77546
Common
03/10/2025
2130
41573.98
The Maetzold 2018 Remainder Trust f/b/o Peter Douglas Maetzold
505 S. Friendswood Drive
Suite 401
Friendswood
TX
77546
Common
01/13/2025
150
4204.41
Derek Maetzold
505 S. Friendswood Drive
Suite 401
Friendswood
TX
77546
Common
01/13/2025
986
27636.99
The Maetzold 2018 Remainder Trust f/b/o Hannah Elizabeth Maetzold
505 S. Friendswood Drive
Suite 401
Friendswood
TX
77546
Common
01/13/2025
150
4204.41
The Maetzold 2018 Remainder Trust f/b/o Emily Carol Kirk
505 S. Friendswood Drive
Suite 401
Friendswood
TX
77546
Common
01/13/2025
150
4204.41
Total number of shares to be sold includes: 3,708 shares by Derek Maetzold, 5,193 shares by DM 2020 Irrev Tr, 6051 shares by Maetzold Descendants 2020 Tr, 495 shares by Hannah Maetzold Irrev. Trust, 495 shares by Peter Maetzold Irrev. Trust, 495 shares by Emily Maetzold Irrev. Trust, 495 shares by John Maetzold Irrev. Trust. The sales of shares set forth herein are made in connection with a selling plan dated 11/11/2024 that is intended to comply with Rule 10b5-1(c).
04/08/2025
11/11/2024
Goldman Sachs & Co. LLC on behalf of Derek Maetzold