Immunohistochemical stainings for E- and N-cadherin, β-catenin, TTF-1 and caveolin-1 in adult human lung. 5A. Type II pneumocytes of alveoli are positive for E-cadherin (arrows). 5B. Epithelial cells of a bronchiole are expressing E-cadherin (arrows). 5C. Cells of alveoli are negative for N-cadherin (arrows). 5 D. Type II pneumocytes (arrows) and to a lesser extent also type I pneumocytes of alveoli are positive for β-catenin. 5E. Epithelial cells of a bronchiole are positive for β-catenin. 5F. Type II pneumocytes exhibit a positive staining for TTF-1 (arrows). 5G. A staining of caveolin-1 is positive in alveolar epithelium (arrows). 5G. A negative control in which the primary antibody has been substituted with non-immune serum. Scale bars = 20 μm.