CGAS and neoplasm: Recent studies have shown that dying tumor cell-derived DNA as a DAMP can activate the cytosolic DNA sensor cyclic GMP-AMP synthase (cGAS) in APCs to convert ATP and GTP to cGAMP8,9, which functions as a second messenger to activate the endoplasmic reticulum (ER) adaptor STING4,10,11 to induce secretion of type I interferons and enhance the activation of antitumor T cell immunity4,12–14.