Second, visceral fat is also an active endocrine tissue, increased secretion of adipose-specific cytokines (e.g., leptin, IL-6, and TNF-α) in patients with obesity or abnormal adipose distribution also inhibits gonadotropin secretion, which in turn inhibits HPG axis (54, 55). The gene discussed is IL6; the disease is obesity due to melanocortin 4 receptor deficiency.