For instance, MKP-1-deficient mice were resistant to diet-induced obesity [17], and skeletal muscle-specific MKP-1 deletion recapitulates the phenotype of global knockout [18]; MKP-3 regulates hepatic gluconeogenesis [19] and increases MKP-4 expression in adipose tissue of db/db mice [20]. This evidence concerns the gene DUSP9 and obesity due to melanocortin 4 receptor deficiency.