KISS1 and osteosarcoma: In this study, we identified two peptides, GnRH and kisspeptin, typically found as key signals within the neuroendocrine reproductive axis, exerting effects on cultured canine osteosarcoma tumor cells in vitro, and further found that the normally-observed stimulatory regulation of kisspeptin on GnRH secretion is recapitulated within these cells.