Vascular cell adhesion molecule 1 (VCAM1),also known as CD106,is a transmembrane glycoprotein belonging to the immunoglobulin gene superfamily. VCAM1 is expressed by cytokine-activated endothelium,interacts with integrin VLA4 (α4β1) present on the surface of leukocytes,and mediates both adhesion and signal transduction. It is also expressed either constitutively or inducibly in a variety of other cell types,including vascular smooth muscle cells,differentiating skeletal muscle cells,renal and neural epithelial cells,macrophages (Kupffer cells),dendritic cells,and bone marrow stromal cells .