As a consequence, the CD4:CD8 ratio was reduced in the CD20+ T compared to the CD20− T compartment in HD (0.6 vs. 1.8, respectively) [4], as well as in the CD3+ pool in both a relapsing-remitting (RR-)MS cohort (1.4 vs. 2.5) and HD [13]. Here, MS4A1 is linked to myeloid sarcoma.