These results were also verified by Western blotting at the protein level, as shown in Figure 3C. It is apparent that after infection with Ad-siGRP78 in ATDC5 cells induced by BMP2, XBP1S expression was enhanced, and overexpression of GRP78 can reduce XBP1S expression in ATDC5 cells induced by BMP2. Here, HSPA5 is linked to infection.