SMN1 and dentin dysplasia: In line with the results of previous studies, we found that biopsies and fibroblasts derived from primary cultures from affected areas in patients with DD had elevated expression levels of TGF-β, in particular the TGF-β1 and TGF-β3 isoforms, and that this correlated with increases in the expression levels of SMA, CTGF, fibronectin and collagen in Dupuytren's fibroblasts compared to controls [18,21].