The Kisspeptin receptor (KISS1R, also named GPCR54) is a member of the G-protein coupled receptor superfamily. The KISS1R natural ligands are peptides called kisspeptins which are encoded by the Kiss gene. The Kiss1 gene was originally discovered by Hershey’s scientists who named it after their famous chocolate, the “Kiss”. The kisspeptins, acting through KISS1R, were found to be potent inhibitors of metastasis in a variety of cancer cell types including thyroid and pancreatic cancer cells. KISS1R and kisspeptins are involved in the direct regulation of the reproductive neuroendocrine axis.nKISS1R is widely distributed throughout the brain, where it is most highly expressed in the hypothalamic and amygdaloid nuclei. High expression was also found within the pancreas and placenta. Lower-level expression was found in a variety of other peripheral tissues including peripheral blood leukocytes, kidney, lung, testes, spleen, thymus, adrenal glands and lymph nodes.