Description: The RM2-5 monoclonal antibody reacts with the mouse CD2 molecule, an approximately 50-55 kDa cell surface receptor expressed by all mouse lymphocytes. Expression of the CD2 antigen in the mouse differs from that of the human in that B lineage cells in the mouse from the pre-B cell stage to mature B cells express CD2. CD2 is a ligand for CD48 in the mouse and is involved in adhesion and activation of T cells.