ISG15 and infection: Seven innate immune response genes (IFNα, Tbk1, Oas2, Cxcl10, Pycard, Isg15, Tlr7) were significantly elevated during acute infection but then subsided by 14 dpi; IFNβ expression was elevated but not significantly so (Fig 2A–2H), indicating activation of antiviral defenses that declined as the virus was controlled.