Recently, immune checkpoint inhibitors (ICIs) like antibodies for programmed cell death-1 (PD-1), programmed cell death-ligand 1 (PD-L1) and cytotoxic T lymphocyte-associated antigen 4 (CTLA-4), have been reported to be the hotspot of HCC immunotherapy, since the interaction between PD-1, CTLA-4, and their ligands (PD-L1 and CD80/86) inhibits T-cell activation. This evidence concerns the gene PDCD1 and hepatocellular carcinoma.