Given the biochemical discrepancy and/or the absence of a tumor on the MRI, we requested the BIPSS in all 12 patients being the main goal to confirm pituitary ACTH secretion and exclude ectopic ACTH production, and to define lateralization of the pituitary adenoma to one or the other side of the pituitary gland. This evidence concerns the gene POMC and pituitary gland adenoma.