PDCD1 and hepatocellular carcinoma: Immune checkpoint inhibitors (ICIs) can lift immune system suppression by blocking these immune checkpoints (10) and thereby enhance antitumor functions (11, 12).In terms of ICI-based immunotherapy, anti-PD-1 antibodies have markedly enhanced the prognosis for patients with advanced HCC, the objective response rate (ORR) reached 17%-20% with certain patients achieving complete response (13, 14).