Asbestos induces lung fibrosis via increased secretion of TGF-β (Manning et al. 2002), particularly in idiopathic pulmonary fibrosis where TGF-β has been localized in association with bronchiolar epithelial cells and their extracellular matrix (Liu and Brody 2001; Pociask et al. 2004). This evidence concerns the gene TGFB1 and pulmonary fibrosis.