CD27 and myeloid sarcoma: Cluster 174403 that identified activated naïve B cells (CD19+CD27-CD38+CXCR5+HLA-DR++CCR4+) had also a significantly higher abundance in MS patients than in HC (data not shown) whereas two clusters of naïve B cells (CD19+CD27-CD38+) were reduced in MS patients compared to HC, including the cluster 174486 expressing low levels of CXCR3 and CCR4, and the cluster 174493 identifying naïve B cells with a low activation level (lower expression of CD44 and CD45RA than other clusters of B cells) (data not shown).