In clinical trials with patients who were obese or diabetic with a predisposition to fatty liver complications including NASH, long-acting FGF21 analogs improved serum and hepatic metabolic parameters and hepatic fibrosis markers, suggesting that FGF21 is a promising therapy for obesity- and meta-inflammation-associated liver diseases [140,168,169]. Here, FGF21 is linked to obesity due to melanocortin 4 receptor deficiency.