Mouse Model UBC13 Enzyme (IMAGE) University of California - San Diego Caption This image depicts a tumor with reduced levels of enzyme UBC13 (top) and a control tumor (bottom) that has spread to the lungs. Credit UC San Diego School of Medicine 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.