ACTA1 and fibrosis: Therefore, in this study, we examined the levels of α-SMA, COL-1 and COL-3, cell morphology, cell proliferation ability, nodule and collagen content, and lung organ coefficient in lung tissue to learn whether the pre-fibrosis model had been constructed in vitro and in vivo and the role of IGF1/IGF1R signaling activation in PF.