A Motile Fibroblast (IMAGE) University of Basel Caption The protein srGAP2, which initiates the repulsion reaction, is heavily concentrated at the front of the cell (below, in red, yellow, and green). Credit University of Basel, Department of Biomedicine 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.