L-selectin is a member of the selectin family of glycoprotein adhesion and homing receptors that recognize sialyated carbohydrate groups and regulate lymphocyte-endothelial cell interactions. It is a type I transmembrane cell adhesion molecule (CAM) and is constitutively expressed on all classes of circulating leukocytes including lymphocytes (excluding memory T-cells), monocytes, and polymorphonuclear (PMN) cells.