Furthermore, at 24 h post-infection, the levels of viral mRNA were significantly downregulated after knockdown of endogenous HRS, Tsg101, VPS28, EAP20, CHMP2B, CHMP4B, CHMP7, VPS4A and ALIX, also VPS37A, VPS37B, EAP45, CHMP1A, CHMP1B, CHMP4A and CHMP4C slightly reduced the amount of viral RNA (Figs 1B and S1C), compared with the control treatment. This evidence concerns the gene VPS4A and infection.