Plasma DPP4 levels are elevated in several settings associated with metabolic dysfunction, such as obesity (13, 14); chronic liver disease, including NAFLD and hepatitis C infection (HCV) (12, 15, 16); as well as type 1 diabetes (17) and T2D (18, 19). This evidence concerns the gene DPP4 and obesity due to melanocortin 4 receptor deficiency.