FGF21 and Insulin resistance: Pharmacological treatment with FGF21 ameliorates age‐related metabolic disorders such as insulin resistance, dyslipidemia, and obesity in rodents (Coskun et al., 2008; Kharitonenkov et al., 2005), and pilot studies in humans indicate that treatment with an FGF21‐analog has beneficial effects on hyperlipidemia and body weight (Gaich et al., 2013).