When WT, cGAS−/− and Stinggt/gt mice were challenged with HSV-1 (strains Mckrae or KOS), we observed severe disease development in mice with a defective cGAS–STING pathway, as shown by disease scores reflecting infection in both the eye (Fig. 1a; Supplementary Fig. 2a,c) and in the CNS (Fig. 1b,c, Supplementary Fig. 2d). Here, CGAS is linked to infection.