CD162 (P-selectin glycoprotein ligand-1, PSGL-1) is a sialomucin constitutively expressed as a disulfide-linked homodimer of two 120 kDa subunits on the surface of circulating leukocytes. CD162 serves as a ligand for P- E- and L-selectin, with the highest affinity for P-selectin. It is thus involved in leukocyte rolling at the endothelial surfaces, prerequisite for firm leukocyte adhesion and subsequent transendothelial migration. CD162 also mediates leukocyte-platelet adhesion and interleukocyte contacts. Whereas serving as an adhession molecule on mature leukocytes, CD162 is a potent negative regulator of human hematopoietic progenitors.