Tracing cancer cells' lineage (IMAGE) University of Pennsylvania Caption Researchers from the University of Pennsylvania used a novel technique based on the CRIPSR-Cas9 system to precisely track the lineage of cancer cells. They found that that one clone (represented by large circle) came to dominate the metastatic cells. Credit University of Pennsylvania Usage Restrictions In context of reporting 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.