Although virus titers were ∼5-fold higher in IFNAR1−/− mice than titers in 129 WT mice on day 5 post-infection, we found that IFNAR1−/− and IFNGR−/− mice showed no increase in susceptibility, pathogenesis or histological outcomes to rMA15 or Urbani virus infection. The gene discussed is IFNAR1; the disease is viral infectious disease.