While we observed that asarinin attenuated BLM-induced pulmonary fibrosis, we also found that the phosphorylation levels of Smad3, AKT, p38, ERK1/2, and JNK in the lung tissue of BLM-induced pulmonary fibrosis mice were significantly increased compared with those in the control group, and asarinin effectively reduced the phosphorylation levels of these proteins (Fig. 2A–D). This evidence concerns the gene SMAD3 and pulmonary fibrosis.