Previous studies have observed the activation of microglial cGAS–STING pathway in exogenous viral infections, traumatic brain injury, cerebral ischemic stroke, and Alzheimer's disease [50, 54–57], however, the activators of cGAS–STING pathway were come from exogenous virus or extracellular nucleic acids released by damaged or dead cells that phagocytized by microglia. This evidence concerns the gene CGAS and viral infectious disease.