Compared with chemotherapy, PD-1/PD-L1 inhibitors increased the risk of all-grade hepatitis (RR = 5.85, 95% CI = 1.85 to 18.46, P < 0.01), and high-grade hepatitis (RR = 5.66, 95% CI = 1.58 to 20.27, P < 0.01). The gene discussed is PDCD1; the disease is hepatitis A virus infection.