TGF-β is likely a central pro-fibrotic growth factor in IPF (51), and although DSP data demonstrated an up-regulated TGF-β signaling pathway (Fig. 3C), Tgfb1 expression itself was not up-regulated in alveolar diseased versus intact ROIs at 15 and 30 dpi (Fig. 6I), suggesting post-translational rather than transcriptional regulation of TGF-β signaling (52). This evidence concerns the gene TGFB1 and idiopathic pulmonary fibrosis.