Journey to Discovery (VIDEO) UT Southwestern Medical Center This video is under embargo. Please login to access this video. Caption UT Southwestern biochemist Dr. Zhijian "James" Chen was named winner of the prestigious 2019 Breakthrough Prize in Life Sciences for his discovery of the cGAS enzyme that launches the body's immune defense against infections and cancers. Credit UT Southwestern 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.