MX1 and infection: Genes involved in the type 1 interferon antiviral response, including BP1, RSAD2, MX2, MX1, ISG15, IRF7, IFITM3, IFIT3, IFIT2, IFIT1, IFIH1, IFI44, which were upregulated in the lungs of C57BL/6 mice, in response to infection with RSV54, were also up-regulated in the calves challenged with BRSV in the present study.