CYP2D6 and hepatocellular carcinoma: ALT level was slightly elevated after therapy in huge HCC patients received DEB-TACE plus apatinib compared to those received DEB-TACE alone, which could be explained as that apatinib selectively inhibited cytochrome P450 enzyme (such as CYP2B6/2B1 and CYP2D6/2D1), which might lead to an impaired liver function and slight elevation of ALT level in huge HCC patients [25].