The increased catalytic activity of this G allele variant and also CYP3A5 has been suggested to increase conversion of sunitinib to its metabolite, SU12662 [22, 23]; excessive accumulation of SU12662 has been associated with grade 3 thrombocytopenia and leukopenia [24]. This evidence concerns the gene CYP3A5 and Thrombocytopenia.