For example, when reported, fibrosis stages were grouped as F0 vs. F1-F4, or F0-1 vs. F2-F3, or F0-2 vs. F3-4 etc. in different studies, which rendered the synthesis of grouping for fibrosis stages insecure; however, FGF-21 levels were higher in NAFLD patients than controls among studies having included patients with NASH-related cirrhosis, which equals with fibrosis stage F4 (Table 4; Fig. S2j), thus providing an indirect indication of higher FGF-21 levels in the end stage of fibrosis. Here, FGF21 is linked to fibrosis.