The Kranzusch lab will investigate how small RNA molecules can activate an immune response to pathogens or cancer. Cells rely on a variety of signaling molecules that direct their response to changing environmental conditions, developmental cues, or signs of infection or disease. As a postdoctoral fellow, I studied a recently identified enzyme named cGAS that generates an RNA signal to broadcast an “alarm” when a cell detects mislocalized DNA or pathogen replication. My lab discovered that cGAS is part of a new family of signaling proteins that includes more than 5,000 enzymes in bacteria and several human proteins of unknown function. Now, using biochemistry, structural biology, and cellular techniques, our group will identify the RNA signals synthesized by these proteins and determine their roles in human immunity and host-pathogen interactions. Our research will explain how cGAS-like enzymes shape the cellular immune response—work that could lead to novel ways of eliminating infections or cancer.