Elevated expression of Cyp17A1 has been reported in the GCs, TCs, and even preovulatory oocytes of PCOS patients [20,21,31], suggesting that gene alterations in GCs and oocytes are responsible for the poor oocyte quality and decreased fertilization rates in IVF patients with PCOS [32]. This evidence concerns the gene CYP17A1 and polycystic ovary syndrome.