While the experimental model for MS, i.e., the adoptive transfer of activated encephalitogenic T cells leading to demyelination, promoted the notion that MS is a T cell-mediated disease for a long time, it was recently elegantly shown that the B cell antigen-presenting (APC) function is crucial for the induction of myelin oligodendrocyte glycoprotein (MOG)-induced EAE. Here, MOG is linked to myeloid sarcoma.