In the literature, various factorsthat may predispose to more severe hepatotoxicity by crizotinib have been proposed,including CYP3A inducers or inhibitors, a previous history of hepatitis C virusinfection, antidiabetic drugs, or collagen disorders.12 But no direct cause-effect relationship has beenestablished. Here, CYP3A4 is linked to hepatitis C virus infection.