Immunofluorescence of lung tissue also showed extensive colocalization of GFP with Grp78, α-SMA, and Collagen I (Fig. 6J), indicating that these supplied exogenous LR-MSC suffered from ER stress and transformed to myofibroblast, which is the likely cause of the failure of treatment for pulmonary fibrosis. Here, HSPA5 is linked to pulmonary fibrosis.