CGAS and cancer: Accordingly, since cancer cells have deregulated cell cycle checkpoints they frequently harbor cytoplasmic DNA, which is increased further upon genotoxic damage and radiotherapy exposure, and can lead to cGAS-STING activation (Chen et al., 2017; Dou et al., 2017; Harding et al., 2017; Mackenzie et al., 2017; Bakhoum et al., 2018; Nassour et al., 2019; Carozza et al., 2020); (Marcus et al., 2018; Schadt et al., 2019; Carozza et al., 2020).