GRN and infection: As shown in Figure8A–C, Realtime PCR results showed that Ad-XBP1S cannot promote BMP2-induced Col II (Fig.8A), Col X (Fig.8B) and RUNX2 (Fig.8C) expression in GEP−/− BMSC cells, however, after infection with Ad-GEP, Ad-XBP1S can increase the expression of Col II (Fig.8A), Col X (Fig.8B) and RUNX2 (Fig.8C) induced by BMP2 in GEP−/− BMSC cells.