Administration of the anti-lymphocyte drug fingolimod to EAE mice caused lymphopenia, improved animal health, enhanced the BBB function during the administration period, and decreased the pro-inflammatory response, but it was accompanied by a "withdrawal effect," defined as a sharp increase in the IL-17 and IFN-gamma to levels higher than those in untreated animals, lymphocyte hyperactivation, worsening symptoms, and increasing BBB permeability after discontinuation of fingolimod. This evidence concerns the gene IL17A and lymphopenia.