KDM6B and obesity due to melanocortin 4 receptor deficiency: Administration of FGF21 shows a wide range of beneficial responses in animals with obesity-related metabolic disorders, including reduction of fat mass, alleviation of postprandial hyperglycemia, attenuation of insulin resistance, improvement of dyslipidemia, hepatic autophagy and prevention of steatohepatitis via histone demethylase Jumonji-D3 (JMJD3/KDM6B) [182,183].