CGAS and viral infectious disease: Cytosolic DNA, originated from DNA damage, mitochondrial stress, and cell death due to viral infection and replication, is recognized by cyclic GMP-AMP synthase (cGAS), that activates stimulator of IFN genes (STING) and activates the TANK-binding kinase 1 (TBK1)-associated pathway, also resulting in the transcription of type I IFN [12,13].