The R2/60 antibody reacts with mouse CD43, a type I transmembrane sialoglycoprotein expressed on the surface of most hematopoietic cells including thymocytes, T cells, B cells, NK cells, monocytes, granulocytes, platelets, and hematopoietic progenitor cells. CD43 binds ligands such as CD54 and CD169 (siglec-1) and plays regulatory roles in cell adhesion, activation, and survival. CD43 exhibits two different glycoforms; a 115 kDa form, and an activation-associated 130 kDa form, both of which are detected by the R2/60 antibody.