The HLA-G molecule can interact with leukocyte receptors (e.g., ILT-2 [LILRB1/CD85j], ILT-4 [LILRB2/CD85d], and KIR2DL4 [CD158d]), mostly on CD8+ T and natural killer (NK) cells, inducing inhibitory cytotoxic responses, facilitating tumor cell proliferation and spread [12]. This evidence concerns the gene KIR2DL4 and neoplasm.