FGF21 and obesity due to melanocortin 4 receptor deficiency: This study contradicts the main result of our meta-analysis, i.e., higher FGF-21 in patients with NAFLD than controls; however, the reasons why FGF-21 was differently regulated by NAFLD and obesity or T2DM were not clear, since their possible effects on FGF-21 are expected to be towards the same direction.