A previous study showed that the administration of sitagliptin (50 mg/day) for 16 weeks resulted in significant decreases in serum HbA1c, AST, ALT and γGT levels in 30 NAFLD patients with T2DM (Iwasaki et al. 2011), a finding that suggests sitagliptin improves the effects of fatty liver. This evidence concerns the gene GPT and type 2 diabetes mellitus.