CD106 is a 110 kD transmembrane protein also known as VCAM-1 and INCAM-110. It is an immunoglobulin superfamily member and is expressed on bone marrow stromal cells, myeloid cells, splenic dendritic cells and endothelial cells (activated by cytokines). CD106 is a counter-receptor for VLA-4 (alpha4beta1 integrin) and LPAM-1 (alpha4beta7 integrin). The interactions of CD106 and VLA-4 or LPAM-1 play an important role in binding of leukocytes to activated endothelial cells and leukocyte extravasation at inflammatory sites.