The E10-286 monoclonal antibody specifically binds to CD329. CD329 is also known as Sialic acid-binding Ig-like lectin 9 (Siglec-9), formerly known as Siglec-Y, which is expressed on peripheral blood monocytes, granulocytes and NK cells. Siglecs (sialic acid/immunolgobulin/lectin) are a family of I-type lectins binding to sialic acids on the cell surface. They are a family of carbohydrate-binding proteins within the immunoglobulin superfamily. Siglecs are all integral membrane proteins with extracellular domains consisting of unusual N-termial V-set Ig domains, followed by variable numbers of C2-set Ig domains.