Background：Platelet endothelial cell adhesion molecule-1 （PECAM-1,CD31） is a member of the immunoglobulin gene superfamily of cell adhesion molecules. It is highly expressed on the surface of the endothelium,making up a large portion of its intracellular junctions. PECAM-1 is also present on the surface of hematopoietic cells and immune cells including platelets,monocytes,neutrophils,natural killer cells,megakaryocytes and some types of T-cell . As well as its role in cell-cell adhesion,PECAM-1 functions as a signaling receptor,and is involved in important physiological events such as nitric oxide production,regulation of T-cell immunity and tolerance,leukocyte transendothelial migration and inflammation and angiogenesis .
