Extra chromosomal DNA (IMAGE) University of California - San Diego Caption Extra-chromosomal DNA, or ecDNA, (indicated by orange and blue arros), are small, circular pieces of genetic information that allow cancer cells to rapidly evolve and become resistant to even the most potent anti-cancer treatments. Credit Mischel research group/Stanford University Usage Restrictions Please credit Mischel research group/Stanford University 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.