Potent and selective S1P1 receptor antagonist (IC50 = 0.93 nM). Exhibits > 3,000-fold selectivity for S1P1 over S1P2, S1P3, S1P4 and S1P5. Induces lymphocyte sequestration in peripheral lymph nodes and upregulates S1P1 receptor expression. Reduces disease severity in mice with EAE. Increases IFN-α production in stimulated dendritic cells in vivo. Purity 98%. MW (observed): 494.98