The high expression of KIR2DL1 (CD158a) and KIR2DL2/3 (CD158b) receptors, especially in patients expressing specific HLA-C ligands, is associated with tumor susceptibility but also with disease progression, with increased expression of these receptors in the NK cells of patients with advanced melanoma [22, 23]. This evidence concerns the gene KIR2DL1 and neoplasm.