Description: The 188 monoclonal antibody was generated against and reacts with mouse B7-H4 also known as B7S1, B7X. Cross reactivity of this antibody to other proteins has not been determined. B7-H4 is a newly discovered member of the B7 family reported to inhibit T cell activation, cell cycle progression and IL-2 production. The ligand for B7-H4 has not been identified yet. Simultaneous double staining of cells with two anti-mouse B7-H4 antibodies, Clone 9 and 188, suggests that epitopes recognized by these mAbs are different and/or there is no steric hindrance when antibodies are used together. 188 stains mouse B7-H4 transfected cells and not spleen cells. Exact expression pattern of B7-H4 has not been fully characterized.