CD69 and relapsing-remitting multiple sclerosis: CD69 was upregulated in MAIT cells from RRMS patients (both in remission and during exacerbations) compared with HCs [4.82 ± 3.61 vs. 0.89 ± 0.54 (p < 0.0001), and 7.39 ± 3.34 vs. 0.89 ± 0.54 (p < 0.0001), respectively; Figure 1D], but not in PPMS patients [1.14 ± 0.69 vs. 0.89 ± 0.54 (p = 0.81); Figure 1E].