Fluorescence microcopy image (IMAGE) University of Freiburg Caption Fluorescence microcopy image of gamma delta T cells (green) attacking cancer cells (blue). To get tot he cancer cells, the immune cells need to navigate through a dense extracellular matrix that surrounds the tumor tissue (red). Image: Credit Katrin Raute / University of Freiburg Usage Restrictions Credit must be given to the creator. Only noncommercial uses of the work are permitted. Adaptations must be shared under the same terms. License CC BY-NC-SA 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.