ACTA1 and pulmonary fibrosis: In our previous study, we enrolled 20 fibrotic PBL patients and 20 healthy controls, and the results showed that both the Notch signaling pathway and the fibrosis marker α-SMA were highly expressed; the correlation analysis showed a significant positive correlation between them (r = 0.898, P < 0.05) [17], which indicated that the Notch pathway was closely associated with the development of pulmonary fibrosis.