TGFB1 and polycystic ovary syndrome: The mRNA expression of TGF-β1 and CTGF, a downstream factor of TGF-β1 that mediates the pro-fibrotic actions of TGF-β1, was increased in granulosa cells of PCOS patients compared with control patients and the histological examination revealed the increased TGF-β1 protein expression in granulosa cells of the ovaries of PCOS patients.