The involvement of miRNAs from host cells and/or HSV-1-encoded miRNAs during viral infections in the regulation of the cytosolic DNA–stimulated type I IFN pathway was investigated by constructing a dual-luciferase reporter carrying a 3′-UTR of signaling protein mRNAs, which included cytosolic DNA sensor molecules IFI16, DDX41, cGAS, and DAI; adaptor molecules STING and TRIF; and other key member molecules IRF3, IRF7, IRF9, TLR9, and TBK1 (Figure 1A). This evidence concerns the gene TLR9 and viral infectious disease.