TGFB1 and idiopathic pulmonary fibrosis: The results show that collagen metabolism imbalance, inflammatory response, and epithelial-mesenchymal transition (EMT) are the core processes in IPF, and the TGF-β1/Smad3 and Wnt/β-catenin pathways are the key signaling pathways for the development of pulmonary fibrosis.