Fingolimod, a modulator of sphingosine-1-phosphate receptor, is the first oral drug approved by FDA for the treatment of relapsing remitting multiple sclerosis, because it reduces the number of circulating lymphocytes in peripheral blood by sequestering them in secondary lymphoid organs through its modulation of the sphingosine-1-phosphate receptor (124). The gene discussed is S1PR1; the disease is relapsing-remitting multiple sclerosis.