When we analyzed two NAFLD subgroups separately (with normal and abnormal glucose metabolism, respectively) and compared the sDPP-4 to that of the CNTRL and T2D groups (in which liver disease was clinically excluded) we concluded that it is the presence of the (fatty) liver disease that has a primary impact on the serum DPP-4 enzymatic activity and not the hyperglycemia alone. This evidence concerns the gene DPP4 and type 2 diabetes mellitus.