mDCs secrete high amounts of IL-12 (94) whereas pDCs secrete high amounts of IFN type I (called the IFN-producing cells) through activation of transcriptional factors such as interferon-regulatory factor 3 (IRF3) and IRF7 to arrest viral infections, although other types of DC also produce IFN type I (such as IFN-α) but in low quantities (12, 23, 95). This evidence concerns the gene IRF3 and viral infectious disease.