Model of ECM Fibers (IMAGE) University of Pennsylvania Caption The researchers' model looked at a dynamic system in which cells' ability to break bonds in the surrounding extracellular matrix influenced their ability to grip their environment and spread throughout it. Credit University of Pennsylvania Usage Restrictions None 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.