PDCD1 and hepatocellular carcinoma: The association between programmed cell death 1 (PD-1) on T cells and its ligand PD-L1 on tumor cells suppresses activation, growth, cytotoxic secretion, and survival of T cells, resulting in cancer immune evasion [10, 11].Previous studies have associated PD-L1 overexpression with aggressiveness, poor prognosis, and recurrence in HCC [12, 13].