CD62P is a type-1 transmembrane protein that in humans is encoded by the SELP gene. It functions as a cell adhesion molecule （CAM） on the surfaces of activated endothelial cells, which line the inner surface of blood vessels, and activated platelets. In unactivated endothelial cells, it is stored in granules called Weibel-Palade bodies. CD62P plays an essential role in the initial recruitment of leukocytes （white blood cells） to the site of injury during inflammation. When endothelial cells are activated by molecules such as histamine or thrombin during inflammation, CD62P moves from an internal cell location to the endothelial cell surface. P-selectin is also very important in the recruitment and aggregation of platelets at areas of vascular injury. CD62P has a functional role in tumour metastasis similar to E-selectin. CD62P is expressed on the surface of both stimulated endothelial cells and activated platelets, and helps cancer cells invade into the bloodstream for metastasis and provides local multiple growth factors, respectively.