Although only limited subjects were investigated , our results suggested that a genetic polymorphism in ABCG2 might alter the transport activity for the drug and elevate the systemic circulation level of irinotecan , leading to severe myelosuppression .
O O O O O O O O O O O O O O O B-GeneOrGeneProduct O O O O O O O O O O O O O O O B-ChemicalEntity O O O O B-DiseaseOrPhenotypicFeature O