When we compared B cells subsets from untreated RRMS patients with those of our healthy subjects’ cohort, we observed a trend toward decreased percentages of naïve B cells (CD19+CD27−IgD+) in untreated RRMS patients (52 vs. 60.7%; p = 0.09) (Figure 1C). Here, CD19 is linked to relapsing-remitting multiple sclerosis.