The WM59 monoclonal antibody specifically reacts with human CD31, a 130-140 kDA type I transmembrane glycoprotein also known as platelet-endothelial cell adhesion molecule-1 （PECAM-1） or Endocam.
CD31 is reported to bind to CD38 and is expressed on platelets, monocytes, granulocytes, and endothelial cells.
It plays a role in angiogenesis, wound healing, cellular migration, and signal transduction.
