Researchers in the Lab (IMAGE) University of California - Berkeley Caption Zhenyu Tang (seated at microscope) examines vascular stem cells in culture along with Aijun Wang (left) and Song Li. The UC Berkeley researchers say that newly discovered stem cells contribute to artery-hardening vascular diseases. Credit Photo courtesy of Song Li Usage Restrictions All rights reserved. Commercial use prohibited. 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.