TGFB1 and idiopathic pulmonary fibrosis: In particular, pirfenidone (an inhibitor TGF-β) [15] and nintedanib (an inhibitor of vascular endothelial growth factor receptors, platelet growth factor, and fibroblast growth factor) [16] are the only medicines that are officially approved for treatment of idiopathic pulmonary fibrosis.