Cell adhesion molecules (CAMs) are a family of closely related cell surface glycoproteins involved in cell-cell interactions during growth and are thoμght to play an important role in embryogenesis and development. The family contains NCAM (for neuronal cell adhesion molecule), ICAM (for intercellular adhesion molecule), VCAM (vascular cell adhesion molecule), PECAM-1 (platelet/endothelial cell adhesion molecule-1), etc. ICAM-1, also referred to as CD54, is an integral membrane protein of the immunoglobulin superfamily and recognizes the B2a1 and B2aM integrins.