IFNB1 and infection: Infection by rMP12-ΔNSs16/198 induced 275, 259, or 220 times more human IFN-β mRNA than mock-infected controls at 4, 8, and 16 hpi, respectively, whereas an increase of human IFN-β mRNA induced by parental rMP-12 was within 6 times, compared to the mock-infected control.