Enzyme (IMAGE) University of California - San Diego Caption When missing a critical signaling enzyme, liver cells (blue) use vesicles (green) to communicate and share resources in order to multiply. Cancer cells may use the same process to resist therapy. Credit UC San Diego Health Sciences Usage Restrictions Use photo credit License Original 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.