POMC and Cushing syndrome due to macronodular adrenal hyperplasia: To explore the mechanism of hypercorticosteronaemia, AdKO mice that had not declared frank Cushing's syndrome, i.e. 5 months females and 10 months males, were injected with dexamethasone to induce a complete blockade of the hypothalomo-pituitary-adrenal (HPA) axis and subsequent suppression of ACTH production (Figure 2C–2E).