In around 80% of cases, endogenous CS is caused by excessive adrenal stimulation from abnormally elevated ACTH levels, due to an ACTH-secreting pituitary tumour (Cushing’s Disease, CD) or by an extra-pituitary ACTH-secreting tumour (ectopic CS), whereas in around 20% of cases CS is related to autonomous, dysregulated cortisol secretion by the adrenal glands [3, 5, 6]. The gene discussed is POMC; the disease is neoplasm.