While physiological concentrations of leptin may exhibit multiple beneficial effects, the hyperleptinemia that is typically found in obesity and diabetes is a major risk factor for the development of atherosclerosis, since it exerts potent proatherogenic effects on multiple vascular cell types (macrophages, endothelial cells, and smooth muscle cells) [119]. The gene discussed is LEP; the disease is obesity due to melanocortin 4 receptor deficiency.