The MHR73-11 monoclonal antibody binds to human CD180, a 105kDA cell surface molecule consisting of extracellular leucine rich repeats (LCC) and a short cytoplasmic tail also known as Bgp-95 and RP105. CD180 is expressed on B cells, dendritic cells, monocytes, and macrophages. It forms a cell surface receptor complex with MD-1 and with TLR4 is involved with the recognition of bacterial lipopolysaccharide (LPS). The MHR73-11 antibody is reported to protect against dexamethasone and irradiation induced apoptosis in B cells.