The comparatively poor aromatization of 11-oxygenated androgens was further highlighted by the inability to detect 11-oxygenated estrogens in serum samples representative of high aromatase expression (pregnancy and cord serum) or high substrate levels (congenital adrenal hyperplasia or adrenocortical carcinoma with elevated 11-oxygenated androgen levels). Here, CYP19A1 is linked to congenital adrenal hyperplasia.