The frequency of this AE (10.5%) was higher than those in previous studies; the incidence of autoimmune hepatotoxicity was reported to be 3‐9% with CTLA‐4 inhibitors20 and 3‐4% with PD‐1 inhibitors.3 In a phase 1/2 trial of nivolumab treatment in HCC patients with or without HBV or HCV infections, 26% of HCV‐infected patients (13/50) and 8% of HBV‐infected patients (4/51) exhibited AST or ALT elevation.21 Therefore, the higher incidence of liver enzyme elevation in the present study could be attributed to the higher proportion of patients with HBV infections (13.5%, 32/237). Here, CTLA4 is linked to hepatocellular carcinoma.