Immunohistochemical stainings for E- and N-cadherin and β-catenin during canalicular period of developing human lung. 2A and 2B. Epithelial cells of a developing bronchiolus (short arrows) and alveoli including pretype II pneumocytes (arrows) are positive for E-cadherin. 2C. Pretype II pneumocytes (short arrows) of alveoli are negative for N-cadherin while epithelial cells of a bronchiolus (arrow) are positive for N-cadherin. 2 D. In addition of the epithelial cells (arrows), some spindle shaped cells of a bronchiole showed also a positivity for N-cadherin (short arrow). 2E, 2F and 2G. Epithelial cells of developing airways including pretype II pneumocytes are positive for β-catenin showing mostly a nuclear positivity (arrows) and also a membrane-bound positivity in some cells (short arrows). 1 H. A negative control in which the primary antibody has been substituted with non-immune serum. Scale bars = 40 μm in 2A, 2C, 2E and 2 H; scale bars = 20 μm in 2B, 2D, 2F and 2G.