CD69 and myeloid sarcoma: While it must be noted that the effector memory cells expressed CD69, indicating they were recently activated, this finding nonetheless has important implications in the context of MS and could suggest that the reactivation of encephalitogenic CD4+ T cells can be carried out not only by non-cognate T-bet+ DN memory B cells, but also by naïve B cells, which are present in the inflamed and steady-state CNS.