CYP19A1 and polycystic ovary syndrome: Apo-lipoprotein AI (Apo-AI) levels are reduced in the serum of patients with PCOS, and the Apo-AI content in granulosa cells proportionally changes the expression of steroidogenic enzymes, including CYP11A, 17-hydroxysteroid dehydrogenation Catalase (HSD), 3-HSD, and CYP19 (85).