Corticosteroid drugs (and endogenous cortisol) potently, broadly, and acutely inhibit the hypothalamic-pituitary-adrenal (HPA) axis, and long-term use can lead to adrenal insufficiency.16 In this trial, boys with DMD showed an unexpected high incidence of adrenal insufficiency at baseline by both ACTH-stimulation and morning cortisol measures. The gene discussed is POMC; the disease is Duchenne muscular dystrophy.