Cas9 Protein to Target DNA (IMAGE) University of California - Berkeley Caption The bacterial enzyme Cas9 is the engine of RNA-programmed genome engineering in human cells. Credit Jennifer Doudna/UC Berkeley 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.