T2D patients with NAFLD have increased serum DPP-4 activity, an enzyme that inhibits incretins such as glucagon-like peptide 1 (GLP-1), and thus, reduced efficacy of sitagliptin (Firneisz et al., 2010; Iwasaki et al., 2012). This evidence concerns the gene DPP4 and metabolic dysfunction-associated steatotic liver disease.