Decologne and colleagues (Decologne et al., 2007) used adenoviral gene transfer of TGF-β to the pleural mesothelium in rats and showed that as well as development of a progressive pleural fibrosis, the pleural fibrosis extended into the lung parenchyma supporting a possible role for mesothelial cells in pulmonary fibrosis. The gene discussed is TGFB1; the disease is pulmonary fibrosis.