INS and obesity due to melanocortin 4 receptor deficiency: Increased FGF21 plasma levels in individuals with obesity, insulin resistance, MASLD and T2DM (Zhang et al., 2008; Ďurovcová et al., 2010; Dushay et al., 2010; Cheng et al., 2011)Treatment with FGF21 analog improves dyslipidemia, decreases body weight and improves fasting insulin levels in patients with T2DM and obesity (Gaich et al., 2013)