Leptin-deficient (ob/ob) mice are an excellent model of obesity and IR Tomita et al. (1992) and are characterized by elevated insulin and glucose levels and by elevated plasma TG and TC, dyslipidemia, and IR (Dubuc, 1976; Fellmann et al., 2013). The gene discussed is LEP; the disease is obesity due to melanocortin 4 receptor deficiency.