IFNB1 and infection: Analysis of copy numbers of murine IFN-β mRNA showed that rAMTV infection induced 1,967, 3,287, or 1554 copies per total RNA (μg) of murine IFN-β mRNA in Hepa1-6 cells at 4, 8, or 16 hpi, which was 1.5, 9.7, or 2.4 times more than that of mock-infected cells (Fig 7B).