INS and obesity due to melanocortin 4 receptor deficiency: Interestingly, FAP has been recently tested as a pharmacological target not only for fibrosis but also as a candidate for anti-diabetic and anti-steatotic therapies since it is involved in the regulation activities of FGF21(a stress-induced hormone with potent anti-obesity, insulin-sensitizing, and hepatoprotective properties) [49–51].