The XMG1.2 antibody reacts with mouse interferon-gamma (IFN-γ), a glycosylated type II interferon comprising a homodimer of ~20 kDa subunits in its active form. IFN-γ is produced primarily by activated T lymphocytes and natural killer (NK) cells in response to antigens, including alloantigens, mitogens, and enterotoxins. IFN-γ binds with high affinity to the α subunit of the IFN-γ receptor, resulting in the ligand-induced assembly of a tetrameric α2β2 receptor complex capable of mediating the cellular response to the cytokine through activation of the JAK-STAT pathway. The IFN-γ receptor is expressed on the surface of all nucleated cells. IFN-γ has important functions in a wide range of biological processes, including macrophage activation, mediating the immune response to viruses and bacteria, and modulating cellular proliferation and apoptosis. The XMG1.2 antibody is suitable for detection of intracellular IFN-γ by methods such as flow cytometry, when paired with an appropriate secondary antibody. The XMG1.2 antibody is also widely used in various assays to neutralize the functional activity of IFN-γ.