sCD163, a marker of activated microglia and macrophages [56]; and CXCL13, necessary for the development of B-cell follicles and secondary lymphoid structures, as a well-known B-cell chemoattractant, produced mainly by follicular dendritic cells and possibly by activated macrophages and microglial cells [57,58]; are promising CSF markers that are under investigation for future use in MS diagnostics [59]. The gene discussed is CXCL13; the disease is myeloid sarcoma.