After initial confirmation of ACTH-dependent Cushing’s syndrome, dynamic function tests like the corticotropin-releasing hormone (CRH) stimulation test and variants of the high-dose dexamethasone suppression test (DST) such as the overnight 8 mg DST are suggested to identify persistent pharmacodynamic effects that are typical for CD (i.e., stimulation of ACTH and cortisol by CRH, and suppression of cortisol by high doses of dexamethasone) (11, 17). This evidence concerns the gene POMC and Cushing syndrome due to macronodular adrenal hyperplasia.