The expression and secretion of many adipokines, such as leptin, resistin, tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), C-C motif chemokine ligand 2 (CCL2), CXC motif chemokine ligand 5 (CXCL5), and angiopoietin-like 2, are up-regulated in AT during obesity. The gene discussed is CCL2; the disease is obesity due to melanocortin 4 receptor deficiency.