Although the histological responses to PD-1/PD-L1 mAbs are diverse, there is a lower incidence of liver irAEs to anti-PD-1/PD-L1 agents than anti-CTLA-4 mAbs, and few records of PD-1/PD-L1 inhibitor-induced hepatitis are available. The gene discussed is CTLA4; the disease is hepatitis A virus infection.