A growing body of studies has equipped NK cells with chemokine receptors (CCRs), such as chemokine receptor chemokine (C-X-C motif) receptor 2 (CXCR2) [316, 317], CXCR4 [318] and CXCR7 [319], to match their cognate ligands expressed on tumor cells, and improved chemoattraction in the antitumor response of NK cells was shown. This evidence concerns the gene CXCR4 and neoplasm.