Although there is some information on potential roles of individual growth factors such as hepatocyte growth factor (HGF), platelet-derived growth factor (PDGF), and TGF-β in periodontitis [68–70] given the considerable number of structural isoforms and the great functional pleiotropy of human growth factor families our knowledge of the role of these mediators is still far from complete. The gene discussed is TGFB1; the disease is periodontitis.