Unexpectedly, a much less severe lesion of pulmonary fibrosis was observed in Mutyh−/− than in Mutyh+/+mice, which was supported by assay on protein levels of TGF-β1 and both fibrotic markers, α-SMA and Vimentin, in pulmonary tissues of the model animals. Here, TGFB1 is linked to pulmonary fibrosis.