The finding that loss of function of the histone demethylase, Jhdm2a, was associated with obesity, decreased expression of metabolically active genes (e.g., Ppar-α and medium-chain acyl-CoA dehydrogenase) in skeletal muscle, and an impaired cold-induced uncoupling-protein- (Ucp-) 1 expression in brown AT (BAT) in rodents also suggested a relationship between epigenetic mechanisms and obesity [131, 132]. This evidence concerns the gene KDM3A and obesity due to melanocortin 4 receptor deficiency.