Leptin deficiency is reported to be accompanied by insulin resistance, obesity, diabetes, and even infertility in experimental models and human.4–6 Leptin receptors exist in many tissues and play an important role in metabolism of lipids and carbohydrates, as well as reproduction system, and immune and inflammatory reactions.7 The role of leptin in the atherosclerosis phenomenon is probably one of its significant roles. The gene discussed is LEP; the disease is diabetes mellitus.