9 Campusano Campusano C C Arteaga Arteaga E E Fardella Fardella C C Cárdenas Cárdenas I I Martínez Martínez P P Cushing syndrome by ectopic ACTH secretion: analysis of the physiopathologic mechanism of hypokalemia. The gene discussed is POMC; the disease is Cushing syndrome due to macronodular adrenal hyperplasia.