TGFB1 and polycystic ovary syndrome: Consistent with this notion, a higher serum level and an increased ovarian expression of TGF-β1 in PCOS patients supports the involvement of TGF-β1 in the pathogenesis of PCOS14, 15, although neither the mechanism regulating TGF-β1 expression nor the role of the upregulated TGF-β1 level in the pathogenesis of PCOS has been elucidated.