IFNB1 and infection: Consistent with this hypothesis, and with the qrtPCR results (Fig. 3B), compared to Hep3B cells infected with VSV-IFNβ (Fig. 3G, lane 2), infection with VSV-IFNβ-IGR P/MC-U led to markedly reduced levels of M protein at both 6 and 18 h post infection (lane 3).