TGFB1 and pulmonary fibrosis: TGF-β1 is a key cytokine in the process of lung fibrosis, and the results of western blot (Fig. 1B, Additional file 1: Figure S1A, and Additional file 4: Figure S4) and immunohistochemistry (Fig. 1D) of TGF-β1 in lung tissues showed that the level of TGF-β1 increased significantly with the increase of fibrosis (p < 0.05).