Abstract
Sphingosine 1-phosphate receptor-1 (S1P(1)), a novel therapeutic target for multiple sclerosis, regulates lymphocyte trafficking, heart rate, and vascular function. The discovery of NIBR-0213, a competitive antagonist for S1P(1) that inhibits autoimmune inflammation while sparing bradycardia (Quancard et al., in this issue of Chemistry & Biology), suggests that fine-tuning of S1P(1) modulators may lead to novel immune modulators with better efficacy to adverse events ratio.