The search strategy was based on specific MeSH terms, including adipocytes, adipose tissue, adipokines, leptin, adiponectin, resistin, obesity, kisspeptins, inflammation, hypothalamus, pituitary gland, ovary, reproduction, fertility and polycystic ovary syndrome, which were used alone or in combination. The gene discussed is KISS1; the disease is obesity due to melanocortin 4 receptor deficiency.