T cell (IMAGE) La Jolla Institute for Immunology Caption A T cell (pictured) can have many roles in the immune system Credit National Institute of Allergy and Infectious Diseases (NIAID) Usage Restrictions No restrictions. License Public Domain 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.