Consistent with the epigenetic downregulation of STING gene expression in cancer cells hampering IFN and cytokine production upon cytosolic DNA stimulation, Qin Yan and collaborators demonstrated that STING mRNA expression is epigenetically downregulated by the histone H3K4 lysine demethylases KDM5B and KDM5C, whereas it is activated by H3K4 methyltransferases. Here, STING1 is linked to cancer.