Secretion of TGF-β1 in cultured fibroblasts harvested from the aforementioned specimens also showed no marked difference [91], but recent real-time PCR and immunohistochemical staining studies found the markedly elevated expression of TGF-β1, p-Smad2, connective tissue growth factor (CTGF), MMP-3 and decreased expression of bone morphogenetic protein-7 (BMP-7) in OSMF. Here, BMP7 is linked to oral submucous fibrosis.