MC2R and chronic primary adrenal insufficiency: This includes transcription of steroidogenic proteins such as StAR, MC2R, melanocortin receptor accessory protein (MRAP, a protein that regulates MC2R expression (Metherell et al., 2005) as well as the orphan nuclear receptor – steroidogenic factor (SF-1) (Sugawara et al., 1996) and the transcriptional inhibitor DAX-1 (the dosage-sensitive sex reversal, adrenal hypoplasia congenital critical region on the X chromosome, gene 1) (Zazopoulos et al., 1997).