IFNB1 and myeloid sarcoma: In this previous study, we found that EBNA-1 IgG titers decreased in the 56.5% of patients treated with natalizumab, 39.1% of patients treated with interferon-beta, and 36.2% of patients treated with glatiramer acetate, after 6 months of treatment, which is significantly lower than the 73.3% found in the current cohort of MS patients treated with teriflunomide.