KLB and type 2 diabetes mellitus: In the cases of FGF21 (Fig. 3A), HNF4α (Fig. 3B), CYP7A1 (Fig. 3C), β-Klotho (Fig. 3E), GS (Fig. 3F), and FGFR4 (Fig. 3G), the T2D-NoR group of patients displayed significantly higher expression levels compared to No-T2D and/or the T2D-R groups.