HLA-G and neoplasm: Mechanistically, HLA-G/ILT-2 or HLA-G/ILT-4 signaling can comprehensively suppress both innate and adaptive anti-tumor immune responses by inhibiting the cytolytic functions of immune-competent cells and promoting immune-regulatory cell proliferation and accumulation, creating a profoundly immunosuppressive and pro-neoplastic TME (28, 29).