Glucagon-like peptide-1 (GLP-1) and, more recently, glucose-dependent insulinotropic polypeptide (GIP) and glucagon (Gcg) receptor (R) agonists have revolutionized T2DM and obesity treatment, restoring insulin sensitivity and often facilitating weight loss in patients [1,2]. The gene discussed is GLP1R; the disease is obesity due to melanocortin 4 receptor deficiency.