Highly selective and potent inhibitor of integrin α4β1 (Very Late Antigen-4; VLA-4) (Kd < 10 pM). Selectively binds α4β1 over a range of other integrins (IC50 values are 1.8, 138, 1053, > 500 and > 10,000 nM for α4β1, α9β1, α2β1, α4β7 and αIIbβ3, respectively). Induces a 30-fold increase in mobilization of murine hematopoietic stem and progenitor cells; displays a 3-fold additive effect with AMD 3100 (Cat. No. 3299). Decreases oxidative damage and improves neurological function following spinal cord injury in rats. Purity 98%. MW (observed): 817.78