CCN2 and pulmonary fibrosis: We next investigated the effect of OSM‐MSCs on the expression of the main extracellular matrix components, including the major profibrotic growth factor, transforming growth factor‐β1 (TGF‐β1), collagen type III and connective tissue growth factor [35], the matrix metalloproteinase‐9, and the tissue inhibitor of metalloproteinase‐1, all of which specifically contribute to lung fibrosis (Fig. 5B–5F).