In order to further investigate whether the decreased expression of POP and Ac-SDKP in the PCOS model mediates the changes of ovarian fibrosis, we treated primary granulosa cells with S-17092, an inhibitor of POP, and found that S-17092 inhibited the expression of MMP-2 and promoted the expression of TGF-β1. This evidence concerns the gene TGFB1 and polycystic ovary syndrome.