In contrast to untransfected control or cells transfected with scrambled siRNA, rosiglitazone did not cause an obvious inhibition of collagen type I gene expression induced by TGF-β1 in PPARγ knock-down cells (Fig 10B).These data indicated that the effects of rosiglitazone on collagen type I gene expression in human ADPKD cyst-lining epithelial cells were PPARγ-dependent. Here, TGFB1 is linked to autosomal dominant polycystic kidney disease.