For these reasons, leptin supplementation to ob/ob mice normalizes their metabolic status [24,25,26,27], whereas leptin sensitizers such as neutralizing leptin antibodies [19], hypothalamic ER stress relievers [28,29,30], and other molecules [31,32] have taken center stage in obesity drug development. The gene discussed is LEP; the disease is obesity due to melanocortin 4 receptor deficiency.