As shown by H&E staining and Masson’s staining, alveolar damage, structural destruction, and accumulation of fibrotic collagen in the alveolar parenchyma, as well as upregulation of messenger RNA (mRNA) expression of α-smooth muscle actin (α-SMA) and collagen 1 (Col 1) after the BLM challenge for 14 days, indicated that the pulmonary fibrosis model was successfully established (Figure 1B–D). This evidence concerns the gene ACTA1 and pulmonary fibrosis.