Given the abovementioned immune suppressive functions of HLA-G in cancer immunology, the HLA-G/ILTs signaling pathway has been recently recognized as a new immune checkpoint in addition to other immune checkpoints such as cytotoxic T lymphocyte-associated protein 4 (CTLA-4)/B7 and programmed cell death protein-1 (PD-1)/PD-L1 (40). The gene discussed is PDCD1; the disease is cancer.