IFIT1 and infection: However, studies of infections of negative-sense RNA viruses of the Orthomyxoviridae, Bunyaviridae, and Filoviridae families with Ifit1-/- mice and the primary cells and human alveolar basal epithelial cells, A549 cells suggested that IFIT1 is not a dominant restriction factor against negative-sense RNA viruses, including OROV [85].