Most findings revealed that HLA-G expression was significantly associated with disease progression and poor survival of patients with cancer; however, the findings were not consistent among different studies or cancer types (12, 13).Mechanistically, through interactions with immune receptors such as ILT2, ILT4, and KIR2DL4, HLA-G could render multiple-level immune suppression function (14). This evidence concerns the gene KIR2DL4 and cancer.