We found that siRNA-mediated knockdown of SLC35B4 expression led to 6.2-/15.9- and 19.4-/21.3-fold, 6.3-/22.2- and 12.4-/19.1-fold, 35.0-/53.0- and 17.1-/26.4-fold, and 2.5-/5.5- and 4.3-/6.9-fold reductions in virus titers for WSN (H1N1), SH13 (H9N2), AH05 (H5N1), and FZ09 (H1N1) virus at 24 hours and 48 hours post-infection (p.i.), respectively (Fig. 1E through H). Here, SLC35B4 is linked to infection.