TGFB1 and idiopathic pulmonary fibrosis: Staining for pSmad2 (a marker for signaling by activated TGF-β) was significantly increased in CF versus HNL by semi-quantitative scoring (CF: 2.5±0.1, HNL: 1.6±0.1, p<0.005) and comparable to that seen for the classical pulmonary fibrotic disease, IPF (2.8±0.1) (Figure 1A and 1B).