Pharmacologically, FGF-21 induced glucose uptake through the induction of glucose transporter-1 (GLUT1) in adipocytes, and in vivo treatment with FGF-21 resulted in amelioration of glucose and lipid metabolism in both murine and nonhuman primate models of diabetes or obesity [11], [14]–[15]. Here, FGF21 is linked to obesity due to melanocortin 4 receptor deficiency.