KISS1 and cancer: Since this initial study (1), KISS1 (145 amino acid), the primary and full-length product of the KISS1 gene and its derivatives (54, 14, 13, and 10 amino acids) called kisspeptins, as well as their cognate receptor KISS1R (previously called GPR54), have been reported to exhibit anti-metastatic and/or anti-tumoral roles in numerous cancers e.g., bladder (2, 3), ovary (4), colorectal (5–7), pancreas (8), pituitary (9), prostate (10), and thyroid (11), as previously reviewed (6, 12–14).