Genes that were upregulated (n = 58) during the first ACTH response included many known GC targets and genes of interest involved in oxidative stress defenses (GPX3), fatty acid oxidation (ACADM), immune function (TLR4), adipogenesis (DKK1), lipid and monocarboxylate transport (SLC16A9), ketogenesis (HMGCS2), insulin resistance and obesity (ZBTB16), NADP biosynthesis and saturated fatty acid metabolism (NADK2), circadian rhythm (PER1), and inactive steroid receptor complexes (FKBP5). This evidence concerns the gene PER1 and obesity due to melanocortin 4 receptor deficiency.