PDCD1 and hepatocellular carcinoma: Immune checkpoint inhibitors (ICI) including anti-cytotoxic T lymphocyte-associated protein 4 (anti-CTLA-4), anti-programmed cell death 1 (PD-1) and anti-PD-L1 antibodies have gained approval for the treatment of a variety of cancers in these years.1 Recent progresses in advanced HCC demonstrate the immunotherapy with ICIs is effective and promising.