The IL17-, IL9-, and IL4-producing CD4+T cell percentages were significantly higher at pre-treatment in MS patients compared with HCs (p<0.01 for all), while the IL17-producing CD4+T cell percentages tended to show a transient increase at 2 weeks of fingolimod therapy (pcorr=0.0834). Here, IL17A is linked to myeloid sarcoma.