Kenneth Tung, UVA Health System (IMAGE) University of Virginia Health System Caption Kenneth Tung, M.D., of the University of Virginia School of Medicine, has discovered an unknown connection between men's testes and the immune system -- a link that could explain infertility and the failure of cancer vaccines. Credit Josh Barney | UVA Health System Usage Restrictions May be used by reporters and webmasters to accompany news coverage of the immune system discovery. All other uses require express written permission from UVA Health System. 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.