Chronic Infection and Interleukin-21 (VIDEO) University of Alabama at Birmingham This video is under embargo. Please login to access this video. To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video Caption Cross-talk between specific T-cells needs interleukin-21 to be effective, says Allan Zajac, Ph.D., an associate professor in the UAB department of microbiology and a lead author on a study that appeared in Science. Credit UAB 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.