In this context, kisspeptin, a 54-amino acid neuropeptide, initially characterised as a metastasis-suppressor gene, and then subsequently identified as a regulator of the hypothalamic–pituitary–gonadal (HPG) axis and reproductive function [4], exerts effects in obesity-related metabolic dysfunction that still need to be fully elucidated. This evidence concerns the gene KISS1 and obesity due to melanocortin 4 receptor deficiency.