In IPF patients, TGF-β1 is mainly secreted by lung macrophages and alveolar epithelial cells and can stimulate the proliferation and activation of fibroblasts, promote myofibroblast formation and ECM deposition, and induce EMT in alveolar epithelial cells [33]. The gene discussed is TGFB1; the disease is idiopathic pulmonary fibrosis.