CD106, otherwise known as VCAM-1 (vascular adhesion molecule 1), a 110kD inducible type I transmembrane glycoprotein and member of the immunoglobulin supergene family, which is predominantly expressed on vascular endothelium, and also on bone marrow stromal cells, follicular dendritic cells and some macrophages. CD106 interacts with the lymphocyte homing receptor VLA-4 (alpha4 beta1 integrin) and LPAM-1 (alpha4 beta7 integrin) and mediates leukocyte-endothelial cell adhesion and signal transduction. Expression of CD106 is upregulated following cytokine activation, and endothelial CD106 plays a role in the extravasation of leukocytes from blood vessels during inflammation.