ABCG2 and Thrombocytopenia: To evaluate the association of ABCG2 421C>A with various sunitinib-induced adverse drug reactions, we performed univariate logistic regression analysis and observed that ABCG2 421C>A is associated with severe thrombocytopenia (P = 1.87x10-2, OR = 1.71, 95% CI = 1.09–2.68), fever (P = 1.59x10-2, OR = 2.85, 95% CI = 1.22–6.66) and increased levels of AST and ALT (P = 4.21x10-2, OR = 2.18, 95% CI = 1.03–4.64).