T cells illustration (IMAGE) Salk Institute Caption Two T cells whose nutritional choices have changed their identity. On the left, a blue T cell prefers acetate and is active, able to continue fighting. On the right, a red T cell prefers citrate and is exhausted, no longer able to fight effectively. Credit Salk Institute Usage Restrictions With credit and related coverage License Original 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.