EFNA1 and myeloid sarcoma: In accordance with the trend towards a decrease in the percentage of positive ephrine-A1 cells among the total T cells of patients with RR-MS, there were decreased percentages of positive ephrine-A1 cells among CD4+ T cells (1.1 ± 0.3%) and Tregs (2.0 ± 0.5%) compared to HC (4.7 ± 1.5%, p = 0.028 and 9.3 ± 3.1%, p = 0.030, respectively, Figure 2A).