CGAS and cancer: Avoiding immune destruction and tumor-promoting inflammation are immune hallmarks of cancer, with the innate immune cyclic GMP-AMP synthase (cGAS) - STimulator of INterferon Genes (STING) pathway involved in both.1–3 The cGAS-STING pathway is a focal point of innate immune responses, activated when cGAS detects cytosolic DNA, producing 2′3′cGAMP and resulting in subsequent stimulation of STING and downstream TBK1-IRF3 and NFκB-RelB pathways.4