Furthermore, intraperitoneal injection of hemin for 4–5 weeks decreased glycemia and improved glucose and insulin tolerance in streptozotocin-induced diabetic rats, Zucker Diabetic Fatty rats, a model of type 2 diabetes with a mutation in leptin receptor and Goto-Kakizaki rats, a nonobese insulin resistant type 2 diabetic model [11,12,13]. Here, LEPR is linked to type 2 diabetes mellitus.