TGFB1 and pulmonary fibrosis: TGF‐β plays pivotal roles in lung fibrosis via mediation of myofibroblast differentiation, epithelial‐mesenchymal transition (EMT), cellular senescence, and epithelial cell apoptosis (Araya & Nishimura, 2010; Hagimoto et al., 2002; Minagawa et al., 2011).