miR-877-3p expression is upregulated in LR-MSCs once they are exposed to TGF-β1, leading to upregulation of myofibroblasts differentiation marker such as fibronectin, αSMA, and collagen I. miR-877-3p also inhibits the Suppressor of Mothers Against Decapentaplegic (SMAD)-7, which inhibits the expression of TGF-β-induced collagen I and αSMA, thus promoting fibrosis through LR-MSC differentiation to myofibroblasts.15 Schematics of the role of MSCs in lung fibrosis are illustrated in Figure 6B and C. Here, ACTA1 is linked to pulmonary fibrosis.