TGFB1 and cyst: In summary, the present study demonstrated that ADPKD cyst-lining epithelial cells were involved TGF-β1 mediated fibrogenesis and rosiglitazone could inhibit TGFβ1-induced collagen type I and fibronectin expression in ADPKD cyst-lining epithelial cells through modulating the Smad pathway but not MAPK pathways.