ST3GAL4 and infection: Interestingly, while both α2,3-linked and α2,6-linked sialic acids are implicated in PEDV infection, the double KO of ST3GAL4 and ST6GAL1, as well as the depletion of SLC35A1, which impacts both types of sialic acid, had the most substantial effect on virus binding, internalization, and infection, suggesting that PEDV may exploit multiple sialic acid subtypes to facilitate infection.