PSGL-1 (CD162), is a mucintype glycoprotein that plays a key role in leukocyte adhesion. Human PSGL-1 cDNA encodes 412 amino acids (aa). It expressed on neutrophils, monocytes and most lymphocytes. The mature PSGL-1 (aa 42-412) is expressed as a disulfide-linked homodimer that signals intracellularly and promotes integrin activation. PSGL-1 is found on virtually all leukocytes, dendritic cells, platelets, and some endothelial cells. It is primarily responsible for early events in extravasation, especially rolling adhesion of leukocytes to vascular endothelium. Through high affinity, This SLe(x)-type proteoglycanPGSL-1 calcium-dependent interactions with E-, P- and L-selectins, mediates rapid rolling of leukocytes over vascular surfaces during the initial steps in inflammation.