Serum FGF21 was higher in patients with T2D throughout the exercise study (P < 0.001), but otherwise no significant differences in expression of FGF21 or changes in muscle expression or serum levels of FGF21 in response to exercise or recovery were observed between patients with T2D and weight‐matched controls (Fig. 2). This evidence concerns the gene FGF21 and type 2 diabetes mellitus.