In an observational study, D Song et al. reported that T2DM patients with NAFLD, who had an elevated serum ALT compared to T2DM patients without NAFLD, obtained a higher risk of DR in the subgroup analyses of Italy and India but a decreased risk for the Chinese, Korean, and Iranian populations, and suggested no relevance for the American population [8]. This evidence concerns the gene GPT and type 2 diabetes mellitus.