The 2021 consensus on diagnosis and management of Cushing's disease reminds that the differential diagnosis between Cushing's disease and Cushing's syndrome by ectopic ACTH secretion relies on a combined approach using ACTH measurement, pituitary imaging, dynamic testing (CRH/desmopressin), inferior petrosal sinus sampling (IPSS), and whole-body imaging (CT, PET), interpreted within the clinical context [10]. The gene discussed is CRH; the disease is Cushing syndrome.