TGFB1 and Hepatic fibrosis: A large part of expression of TGF-β1 and TGF-β3 in the liver comes from the secretion of HSC; as both TGF-β1 and TGF-β3 play an important role in the regulation of HSC activation and liver fibrosis, their expressions perhaps reflect a side of the activation of HSC; moreover, change or imbalance of the ratio of TGF-β1/TGF-β3 may be involved in the immune response or progression of liver fibrosis.