The BM8.1 monoclonal antibody specifically binds to the Mouse125 kDa F4/80 antigen, expressed by most mature macrophages. F4/80 is a transmembrane protein used as a Markerofmacrophages,althoughitisalsoexpressedonKupfferandLangerhanscells.TheexpressionofF4/80antigenisupregulatedonbonemarrowcellsstimulatedinvitrowiththemacrophagecolonystimulatingfactor.TheF4/80antigenisarequirementfortheinductionofCD8Tcells-mediatedperipheraltolerance.