Upon infection by DNA viruses or bacteria, microbial DNA delivered into the cytosol stimulates the production of type I interferon (IFN) through stimulator of IFN gene (STING), which triggers phosphorylation of IFN-regulatory factor 3 (IRF3) by TBK1 to promote nuclear translocation and transcriptional activation of genes, including IFNβ20–22. Here, TBK1 is linked to infection.