Among ACTH-dependent cases, 80–90% are caused by pituitary adenomas (Cushing’s disease), while 10–20% result from ectopic ACTH secretion, often due to bronchial, thymic, or pancreatic neuroendocrine tumors (NET), pheochromocytomas, or small-cell carcinomas [3]. The gene discussed is POMC; the disease is small cell carcinoma.