Integrins are cell-surface proteins that regulate interactions in the extracellular matrix, and several studies by our group have demonstrated that the epithelial integrin αvβ6 is critical for TGFβ activation in models of acute lung injury and pulmonary fibrosis (Munger et al., 1999; Huang et al., 1996; Pittet et al., 2001; Breuss et al., 1993). The gene discussed is TGFB1; the disease is pulmonary fibrosis.