As many of the side effects that we wish to avoid in CAH relate primarily more to over- and/or undertreatment with hydrocortisone rather than adrenal androgen excess, it is worth considering a change in our thinking towards placing cortisol at the centre of replacement therapy and using cortisol as the primary measure to ensure optimal cortisol concentrations which will normalise ACTH and androgen levels in CAH. The gene discussed is POMC; the disease is congenital adrenal hyperplasia.