Abstract < /h3 > < span class= " a-plus-plus abstract-section id-a-sec1 " > < h3 class= " a-plus-plus " > Purpose of Review < /h3 > < p class= " a-plus-plus " > Epithelial cells line tissues and serve an important functional role in maintaining a barrier between tissue compartments and protection from the external environment. Tight Junctions and apical –basal polar..."> Abstract < /h3 > < span class= " a-plus-plus abstract-section id-a-sec1 " > < h3 class= " a-plus-plus " > Purpose of Review < /h3 > < p class= " a-plus-plus " > Epithelial cells line tissues and serve an important functional role in maintaining a barrier between tissue compartments and protection from the external environment. Tight Junctions and apical –basal polar..." /> Abstract < /h3 > < span class= " a-plus-plus abstract-section id-a-sec1 " > < h3 class= " a-plus-plus " > Purpose of Review < /h3 > < p class= " a-plus-plus " > Epithelial cells line tissues and serve an important functional role in maintaining a barrier between tissue compartments and protection from the external environment. Tight Junctions and apical –basal polar..." />