CXCL8 and asthma: Most notably in the context of asthma, FTY720 can induce sphingosine 1-phosphate (S1P) signaling and we have previously shown that S1P is elevated in allergic asthma29, drives development of the pro-asthmatic phenotype, and can induce IL-6 and IL-8 expression29, 30, 31 .