Viral infection would provide cGAS with sufficient agonists and release cGAS from the plasma membrane to facilitate its signalling in the cytosol.61 The nucleus-localised cGAS might facilitate the detection of viruses that only expose their DNA in the nucleus, and the nucleosome structure of self-DNA and special localisation of cGAS in the nucleus might enable cGAS to discriminate self-DNA from viral DNA.62–64 Thus, the intracellular distribution of cGAS provides surveillance that covers sites where pathogens release their DNA while trying to avoid aberrant self-DNA detection. The gene discussed is CGAS; the disease is viral infectious disease.