Apparently, the downregulation of key regulatory genes in epithelial cells and the enhancement ofthe immune related signaling pathways, particularly TGF-β signaling, which is a marker ofepithelial-mesenchymal transition (EMT), suggest a loss of epithelial integrity andepithelial-mesenchymal balance in patients with asthma. This evidence concerns the gene TGFB1 and asthma.