Immunotherapy has demonstrated great potential in treating a variety of cancers, in particular immune checkpoint inhibitors (ICI) targeting cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) or Programmed death-ligand 1 (PD-L1)/Programmed cell death protein 1(PD-1) (5, 6). This evidence concerns the gene PDCD1 and cancer.