TGF-β, a critical pro-fibrogenic cytokine induced by ROS, has been demonstrated to contribute to a broad spectrum of events taking place during the pathogenesis of pulmonary fibrosis such as differentiation of fibroblasts into active myofibroblasts (Lee et al., 2006), synthesis and deposition of ECM molecules by myofibroblasts (Ignotz and Massagué, 1986) and EMT (Willis and Borok, 2007). The gene discussed is TGFB1; the disease is pulmonary fibrosis.