Sources of cytoplasmic DNA include bacteria, viruses, tumor cells, micronuclei, damaged mitochondria, etc. cGAS senses DNA from the above sources and undergoes conformational changes, thereby catalyzing the synthesis of the second messenger cGAMP containing 2′-5′ and 3′-5′ phosphodiester bonds from ATP and GTP (Ablasser et al., 2013; Gao et al., 2013; Zhang et al., 2013). This evidence concerns the gene CGAS and neoplasm.