The rationale for the use of cabergoline in CD was the demonstration that the dopamine receptor subtype 2 (D2) is expressed in approximately 80% of human corticotroph adenomas and that these adenomas can be responsive to the ACTH-inhibiting actions of D2-agonists in vitro [42, 43]. This evidence concerns the gene POMC and ACTH-producing pituitary gland adenoma.