Cancer Cell Competition within a Zebrafish (image) Harvard University Share Print E-Mail Caption To identify the mutations that generated the most relapse-prone leukemia, the researchers competed single cancer cells against each other within a zebrafish. Credit Jessica Blackburn/Massachusetts General Hospital Usage Restrictions The image may only be used with appropriate credit. Share Print E-Mail 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.