Studies of the steroid profile of patients with congenital adrenal hyperplasia due to deficiencies of 17α-, 11β- or 21-hydroxylase (and POR), corroborate this physiological data, reinforcing the concept of a “MC (or non-17-hydroxylated) pathway of ZF” (3,7-9,18). Here, POR is linked to congenital adrenal hyperplasia.