In addition to immune effects, both LPA and S1P receptors are widely expressed in the CNS where they are likely to have a range of direct CNS activities relevant to both EAE and MS, as demonstrated by a requirement for astrocyte S1P1 for fingolimod activity in EAE [5, 24] and LPAR1 for myelination [23]. Here, S1PR1 is linked to myeloid sarcoma.