HSV-1 inhibits IFNα-induced ISG15 expression in an ICP27-independent manner. Vero cells were mock infected (lanes 1–2) or infected (MOI = 20) with wt HSV-1 (KOS, lanes 3–4), or ICP27− virus (5dl1.2, lanes 5–6) and treated with IFNα (even lanes) for 2 hours before harvest. Western blot analysis was done with antibodies specific for pStat-1, ISG15, and GAPDH.