In the subgroup analysis for the comparison between patients with NAFLD and controls among studies with and without histological confirmation of the disease, there was no difference between subgroups (p = 0.590); circulating FGF-21 was higher in patients with NAFLD than controls within both subgroups (Table 4; Fig. S2 g-i). This evidence concerns the gene FGF21 and metabolic dysfunction-associated steatotic liver disease.