A critical role for tissue DNA as an autoimmune trigger emerged in mice lacking DNA catabolizing enzymes, which succumbed to spontaneous, lethal autoimmunity due to sustained cytosolic DNA sensing to activate the signaling adaptor Stimulator of Interferon Genes (STING), a potent IFNβ inducer (2, 3). The gene discussed is STING1; the disease is Autoimmunity.