Description: The AK-4 monoclonal antibody reacts with human CD62P, a 140 kDa transmembrane glycoprotein also known as P-Selectin. Upon activation, CD62P is rapidly transported from its cytoplasmic stores in the Weibel-Palade bodies of endothelial cells or the alpha-granules of platelets to the surface. CD62P initiates the adhesive interaction between endothelial cells and neutrophils and monocytes during the inflammatory reaction and is also involved in the interaction of platelets with monocytes and neutrophils.