Only 1.2 % of all patients with Cushing’s syndrome were due to ACTH secretion from a pheochromocytoma or an adrenal medullary hyperplasia, and only 1.3 % of all pheochromocytomas identified also resulted in an ectopic ACTH syndrome. This evidence concerns the gene POMC and Cushing syndrome due to macronodular adrenal hyperplasia.