TGFB1 and pulmonary fibrosis: Although the origin and pathogenesis of pulmonary fibrosis is complex, TGF-β1 has been implicated as a key player in the pathogenesis of pulmonary fibrosis, as it may induce proliferation and differentiation of fibroblasts, epithelial-mesenchymal transition (EMT), and transformation of lung fibroblasts to myofibroblasts, which eventually lead to serious pulmonary fibrosis in vivo and in vitro17, 18, 19.