PDCD1 and hepatocellular carcinoma: Immune checkpoint inhibitors, such as programmed cell death protein 1 (PD-1) and its ligand (PD-L1), have become one of the new standard of care for first- and second-line treatment of advanced hepatocellular carcinoma (12, 13) in recent years, as they continue to demonstrate good efficacy in the treatment of advanced hepatocellular carcinoma.