The Anti-Mouse IL-21R (Clone 4A9) - PE - 50 µg Antibody from Leinco Technologies, Inc. is a Rat Monoclonal antibody to IL21, and Interleukin 21. This antibody recognizes Mouse antigen. The Anti-Mouse IL-21R (Clone 4A9) - PE - 50 µg Antibody has been validated for the following applications: Flow Cytometry.