In addition, TGF-β1 stimulates fibroblast chemotaxis toward fibronectin [7, 8] and augments fibroblast-mediated contraction of ECM by stimulating contractile stress fibers (α-smooth muscle actin [α-SMA]) [9], generating lung fibroblasts that can be used as in vitro model of lung fibrosis. The gene discussed is FN1; the disease is pulmonary fibrosis.