ACTA1 and pulmonary fibrosis: Bleomycin-induced pulmonary fibrosis was associated with increased serum levels of exosomal miR-22 and fibrotic pathology was ameliorated with a miR-22 mimic due to its ability to inhibit TGF-β1-induced expression of αSMA or profibrotic cell communication network factor 2 (CCN2; also known as connective tissue growth factor) in lung fibroblasts in vitro [77].