PDCD1 and hepatocellular carcinoma: The primary drugs utilized for immunotherapy for HCC are immune checkpoint inhibitors (ICI), specifically anti-cytotoxic T-lymphocyte antigen 4 (CTLA-4) and anti-programmed cell death 1 (PD-1/PD-L1) monoclonal antibodies, which have been extensively employed in the treatment of HCC (6).