Increased TGF-β signaling in lung tissue from cystic fibrosis (CF) and idiopathic pulmonary fibrosis (IPF) compared to non-CF human normal lung tissue (HNL).

<p>A) Immunohistochemical staining for phosphorylated Smad2 (pSmad2 shown in brown). The downstream signal of TGF-β is significantly increased in CF compared to HNL tissue and comparable to that seen in IPF. Images are shown at approximately 100× from 2 separate CF, HNL and IPF specimens (bar = 250 µm). B) Comparison of TGF-β signaling (pSmad2 staining) by semiquantitative score (1–5). C) Comparison of TGF-β signaling (pSmad2 expression) by quantitative morphometry. D) Correlation between semiquantitative scale (1–5 scale) and morphometric measures of pSmad2.