The Interferon- alpha/ beta Receptor 1 (IFN- alpha/ beta R1) is a receptor which binds Type I Interferons including Interferon- alpha and - beta . It is a cell surface receptor and heteromeric receptor composed of one chain with two subunits referred to as IFNAR1 and IFNAR2. IFN- alpha/ beta R1, in association with IFN- alpha/ beta R2, is required for propagating antiviral signal transduction triggered by IFN- alpha and IFN- beta . IFN- alpha/ beta R1 interacts very weakly or not at all with type 1 interferons and does not stably interact with IFN- alpha/ beta R2. Ligands associate with IFN- alpha/ beta R2, and this complex subsequently forms a stable ternary assembly with IFN- alpha/ beta R1. IFN- alpha/ beta R1 also associates with IFN- gamma R2 even in the absence of IFN- gamma stimulation. Human IFN- alpha/ beta R1 contains a nuclear localization signal in its extracellular domain that is required for receptor translocation to the nucleus following interaction with ligand. Interferon stimulation results in an immunologic response that is especially associated with viruses.