 The adherence junction, AJ, is an actin filament anchoring junction that is essential for epithelial morphogenesis. It is composed of catherans, which bind to each other and to alpha-catenin, which acts as a tension transducer that changes its confirmation in response to tension. This tension sensitivity of alpha-catenin is important for the proper rounding morphogenesis of epithelial cells. This article was authored by Riosuke Nishimura, Kageaki Kedo, Misako Saita, and others.