Interestingly, both ILC1 and ILC3 subsets expressed Sphingosine-1-phosphate receptor 1 (S1PR1), which explains their reduced absolute numbers in the peripheral blood of RRMS patients treated with Fingolimod, a sphingosine 1-phosphate receptor modulator used as a first-line therapy for RRMS, compared with treatment-free pwMS (187), suggesting that S1PR1 agonist sequesters peripheral blood human ILCs in lymph nodes. This evidence concerns the gene S1PR1 and relapsing-remitting multiple sclerosis.