Turning on T Cells (IMAGE) California Institute of Technology Caption Researchers imaged cells to identify proteins that affect the expression of a genetic switch for T cells. On the right, T cells where the switch is activated glow in yellow. On the left, the rainbow pattern, a hierarchical cluster analysis, tells researchers which genes are controlled by the switch. The horizontal stripes are the genes. If they stripes turn red going from left to right, it means they are turning on; if they turn blue, the genes are turning off. Credit Caltech Usage Restrictions Please use the Caltech credit. 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.