Description: The R1-2 monoclonal antibody reacts with mouse CD49d, the 150 kDa integrin alpha4 subunit. The complex of CD49d non-covalently associated with integrin beta1 (CD29), also known as VLA-4, is a receptor for fibronectin and VCAM-1 (CD106). This complex is expressed by thymocytes, peripheral lymphocytes, monocytes and eosinophils. CD49d also associates with integrin b7 and binds to the Mucosal vascular Addressin (MAdCAM-1).