STAT1 and infection: We previously used ‘conventional’ assays where cells are treated with IFN following transfection with luciferase plasmids and either co-transfection with plasmids to express viral proteins, or infection by virus; this approach showed that Ni-CE P protein is less able to inhibit IFN/STAT1 signaling than Ni-P protein, in transfection and infection systems [25].