The cytoplasmic nucleotide transferase cGAS senses tumour-derived DNA in the cytoplasm of dendritic cells and further catalyses the synthesis of cyclic GMP–AMP (GAMP) to bind and trigger STING, which then promotes type I IFN responses to initiate antitumour responses and enhance CD8+ T cell cross-priming [20]. The gene discussed is STING1; the disease is neoplasm.