T Cells Targeting Tumor Cells (IMAGE) City of Hope Caption Blue indicates the cell nuclei (big: tumor cell; small: T cell). The aggregation of yellow color at the interface between the two cells is the formation of immune synapse, a key indicator of T cell activation which will lead to tumor killing. Credit City of Hope 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.