TGFB1 and idiopathic pulmonary fibrosis: TGF-β1 percentage was considerably greater in intima and media layers compared to adventitia in smaller-sized arteries of 100–199 μm (p < 0.001) (Figure 1B), and TGF-β1 percentage was significantly higher in intima (p < 0.0001) and adventitia (p < 0.05) compared to medial layer in medium-sized arteries of 200–399 μm in IPF patients (Figure 1C).