Immunohistochemical stainings for E- and N-cadherin and β-catenin during pseudoglandular period of developing human lung. 1A and 1B. Epithelium of the developing airways is positive for E-cadherin (arrows). 1C and 1 D. Epithelium of some developing airways is positive for N-cadherin (arrows) whereas other developing airways are negative for N-cadherin (short arrows). 1E and 1F. Epithelial and mesenchymal cells of developing airways are positive for β-catenin. In most airways epithelial cells display nuclear positivity (arrows) whereas some airways exhibit membrane-bound positivity (short arrows). 1G. A high power field image showing nuclear positivity for β-catenin in epithelial cells of a small developing airway (arrows) surrounded by positively stained mesenchymal cells (short arrows). 1 H. A negative control in which the primary antibody has been substituted with non-immune serum. Arrows are indicating developing airways. Scale bars = 40 μm in 1A, 1C, 1F and 1H; scale bars = 20 μm in 1B, 1 D and 1G, and scale bar = 80 μm in 1E.