We found that lean and obese PCOS patients demonstrated different enzyme activity for P450c17, P450c21, 3βHSD2, and P450aro; among these, P450c21 (catalyzing the 21-hydroxylation of P to DOC and 17-OHP to S) was reported to be found solely in the adrenals28. The gene discussed is CYP17A1; the disease is polycystic ovary syndrome.