However, CS can also occur from an endogenous cause, e.g., ACTH (adrenocorticotropic hormone)-dependent, about 80%; Cushing’s disease (CD); ectopic ACTH-secreting tumours; CRH (corticotropin-releasing hormone)-secreting tumours; and ACTH-independent (20%; adrenal tumour, carcinoma and macroscopic overgrowth (AIMAH)). This evidence concerns the gene CRH and neoplasm.