UT Southwestern biochemist Zhijian "James" Chen, Ph.D., famously identified the cGAS enzyme pathway that alerts the human immune system to disease-causing invaders like viruses. Since then, researchers have found that cGAS signaling is an ancient, conserved defense strategy stretching from bacteria to mammals. A new study from the Chen lab published in Nature reports a novel mechanism bacteria use to enhance the effectiveness of the cGAS-mediated immune response.