As TRIM21 expression is tightly regulated by IRF pathways and the end-products, IFN-α and IFN-β, as well as IFN-γ [58], and as these cytokines are produced in response to HSV-1 infection [61,67,68], we investigated whether increased susceptibility to infection was reflected by changes in IFN levels or IFN-inducible gene expression. The gene discussed is IFNB1; the disease is infection.