NR3C1 and obesity due to melanocortin 4 receptor deficiency: Systemic glucocorticoid levels are generally normal in patients with common forms of obesity or overweight type 2 diabetics.[17] Since GR signalling depends not only on the circulating glucocorticoid level, but also on the prereceptor activation of glucocorticoid within cells, it is speculated that the intracellular glucocorticoid concentration is responsible for metabolic disorders.