TGFB1 and idiopathic pulmonary fibrosis: Lung fibroblasts from IPF patients and in vivo models demonstrate that the antifibrotic activity of nintedanib is associated with the inhibition of pro-fibrotic mediators, including platelet-derived growth factor (PDGF) and fibroblast growth factor (FGF), transforming growth factor beta (TGF-β), and vascular endothelial growth factor (VEGF).