ICIs—such as programmed death-1 (PD-1), programmed death-ligand 1 (PD-L1), and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4)—have shown remarkable efficacy in treating malignancies, including hepatocellular carcinoma (HCC) and melanoma [1]. The gene discussed is CTLA4; the disease is hepatocellular carcinoma.