ACTA1 and pulmonary fibrosis: To further verify mTOR activation during the fibrosis process, we performed immunohistochemical staining with α-SMA and p-S6 antibodies in lungs from a bleomycin-mediated pulmonary fibrosis animal model by day 21 after bleomycin intra-tracheal injection in wild-type C57BL/6J mice.