ISG15 and Hand-foot syndrome: The regulation profile of all of the potentially IRF3-dependent, IFN-independent genes identified in our literature screen, i.e., IFIT1, IFIT2, IFIT3, CXCL10, Mx1, Mx2 (Figure 1) and ISG15 (Figure 2a) was similar to that observed for viperin, in that upregulation was observed in the primary HFs and V/HFs but not in the nPro/HFs.