To examine whether the down-regulation of the 91 ‘top hits’ affects the intracellular localization of the viral proteins in virus-infected cells, siRNA-transfected HEK 293 cells were infected with 200 pfu of WSN virus per well of a 24-well tissue culture plate, fixed at 12 h post-infection, and then stained with an anti-HA, anti-NA, anti-NP, or anti-M1 antibody. The intracellular localization of HA (A), NA (B), and NP (C) is shown. None of the siRNAs affected M1 localization. See also Figure S4 and Table S5.