Biosensor reveals unexpected variability in the cGAS response to DNA damage

Nature Cell Biology, Published online: 21 August 2026; doi:10.1038/s41556-026-02039-y We present an updated reporter as the most sensitive readout for cGAS activation. Using this biosensor, we show that cGAS activation during genotoxic stress is rare, and that it is not driven by micronuclei. Instead, subsets of chromosome bridges and complex DNA structures containing DNA–RNA hybrids were found to activate cGAS.