Figure 4. SIRT1 potentiated BMP2-induced chondrogenesis in vivo. (A) Macrographic images of the ectopic bone mass. The ectopic osseous masses were retrieved after 2 and 4 weeks. (B) The bone mass volumes were evaluated. (C) The bone masses retrieved from the Ad-BMP2 and Ad-BMP2+Ad-SIRT1 group were fixed and decalcified, and hematoxylin and eosin, Alcian blue, and Masson trichrome staining was performed on the extracted bony mass (200X). NS: p > 0.05.