ISG15 and infection: These nPro/HFs and V/HFs were recently utilized, alongside IRF3 KO CRISPR/Cas9 HFs, to demonstrate that expression of viperin, ISG15, IFIT1, IFIT2, IFIT3, Mx1, and Mx2 mRNA during infection with HCMV can be induced in an IRF3-dependent, STAT1-independent manner (96).