A selective S1P1 receptor agonist (EC50 = 1.2 nM); highly selective for S1P1 with EC50 values of >10,000, 1,210, >1,000, and 340 nM for S1P2, S1P3, S1P4, and S1P5 receptors, respectively; reduces circulating lymphocytes and prevents rejection of rat heart allografts; almost completely prevents peripheral paralysis and decreases inflammation in a rat model of experimental autoimmune neuritis at a chronic dose of 10 mg/kg per day