TLR9 activation by CpG-ODN treatment induced the differentiation of IPF but not normal lung fibroblasts into myofibroblasts as evident by increased αSMA expression (Meneghin et al., 2008), induced the differentiation of TGF-β treated blood monocytes into CD45+ αSMA+ COL1+ fibrocytes, and induced the Epithelial to Mesenchymal Transition (EMT) of the type II alveolar epithelial cell line, A549 cells (Trujillo et al., 2010b). The gene discussed is TLR9; the disease is idiopathic pulmonary fibrosis.