As it has been shown that down-regulation of NKG2D activating ligands, such as UL16 binding protein 1 (ULBP1), ULBP2, ULBP3, and MHC class I chain-related molecules A and B (MICA, and MICB), are key pathways for tumor cells to escape from NK cell-mediated cytotoxic action17, NKG2D ligands are also emerging as a potentially important target in immunotherapy18. This evidence concerns the gene KLRK1 and neoplasm.