TGFB1 and pulmonary fibrosis: After induction of lung fibrosis by TGF-β1 (92), thorax irradiation (91) or by bleomycin treatment (93) the authors reported the appearance of expression of different mesenchymal markers (α-SMA, vimentin, S100A4) in β-gal-positive cells and the co-expression of mesenchymal markers and pro-surfactant C (a marker of AET II cells) (91–94).