POSTN and Hepatic fibrosis: In these models, TGF-β1 and TGF-β2 RNA expression and serum levels were correlated with presence of periostin: activated HSCs were able to produce periostin upon TGF-β1 stimulation, and periostin-deficient mice with acute and chronic hepatic fibrosis showed a significantly lower expression of TGF-β1 and TGF-β2 compared to wild-type mouse models of fibrosis.