In the human tracheal/bronchial epithelium, ciliated cells display mainly a2,3linked SAs and goblet cells express a2,6linked SAs [19] . About one third of ciliated cells also display the a2,6-linked SAs and goblet cells also express the a2,3-linked SAs at a low degree [19, 20] . The distribution of the a2,3and a2,6-linked glycans was primarily on the apical surface of both ciliated and goblet cells, respectively [19, 20] . As revealed by specific lectins and ICC staining in the primary CTE cells, our results clearly illustrate that all three types of CTE cells express SAa2-3Gal in a varied degree. SAa2-3Gal showed abundant expression on chicken ciliated cells but only a detectable level on basal cells ( Fig. 6 and Table 1 ).