TGFB1 and pulmonary fibrosis: It is the chemotactic for fibroblasts, induces the synthesis of matrix proteins and glycoproteins, and inhibits collagen degradation by induction of protease inhibitors and reduction of metalloproteases.[15,16] In light of the relevance of TGF-β1 to the development of fibrosis, there are a large number of studies conducted to investigate the association of TGF-β1 polymorphisms with the development of pulmonary fibrosis.