Integrin alpha 4, beta-1 (VLA-4) plays a major role in lymphocyte extravasation, via binding to VCAM on endothelial cells. VLA-4 also binds fibronectin and mediates homotypic and heterotypic cell-cell adhesion between lymphocytes. Combines with beta-1 integrin to form VLA-4, an adhesion receptor involved in cell-cell adhesion and activation of leucocytes
