Here we show that the beneficial effects of IFN beta in multiple sclerosis may in part be mediated by modulation of ILT3 and ILT4 expression on APC.The role of immunoregulatory receptors in CNS inflammation is further highlighted by their enrichment in cerebrospinal fluid and an upregulation of ILT3, ILT4, and B7-H3 in acute MS lesions. This evidence concerns the gene LILRB4 and myeloid sarcoma.