The p53 mutation spectrum , presenting a high level of CC to TT mutations , shows that the UV component of sunlight is the major risk factor and modulated DNA repair by immunosuppressive drug treatment may be significant in the skin carcinogenesis of RTRs .
O B-GeneOrGeneProduct O O O O O O O O B-SequenceVariant I-SequenceVariant I-SequenceVariant O O O O O O O O O O O O O O O O O O O O O O O O O O O B-DiseaseOrPhenotypicFeature I-DiseaseOrPhenotypicFeature O O O