ACTA1 and pulmonary fibrosis: Results of gene expression of (fibronectin, vimentin, α-SMA, and Smad2/3) in MCR-5 revealed that cells treated with TGF-β1 only (10 ng/ml) expressed high levels of the targeted genes, proving the fact that TGF-β1 is a fibrogenic cytokine and a key player and regulator in the development and progression of pulmonary fibrosis by promoting the activation, proliferation, and migration of fibroblasts, ECM deposition and the transformation from fibroblasts to myofibroblasts84,85.