Similarly to CF tissues, fully differentiated primary CF bronchial epithelial cells show increased levels of mesenchymal markers (N-cadherin and vimentin), although not accompanied by decreased levels of epithelial markers (CK18, ZO-1 and E-cadherin), and correspondingly have a decreased TEER, suggesting impaired cell-cell contacts. This evidence concerns the gene KRT18 and cystic fibrosis.