Schematics (IMAGE) National University of Singapore Caption These are schematics showing the arrangement of cells in normal epithelial tissue (a), following the introduction of a topological defect (b) and the site of cell death and extrusion following the appearance of a topological defect in the epithelial layer (c). The blue gradient region represents a concentration of compressive force. Credit Mechanobiology Institute, Singapore Usage Restrictions Please credit image accordingly License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.