Type I interferons (IFNα/β) are pivotal to anti-viral defense. Although an absolute requirement for viral clearance, the presence of IFN in high doses sustained over time has been implicated to be the underlying cause of clinical outcomes such as interferonopathies. Therefore, tight regulation of cellular communication processes is required for tissue homeostasis. This review covers the cellular signaling pathways initiated by DNA sensing through cGAS in the cellular cytosol, with particular focus on the subsequent establishment of immune responses in bystander cells.