B2M and myeloid sarcoma: Although their cellular source maybe different, previous data indicated their protective role in experimental models: UFO (Axl) promotes remyelination and oligodendrocyte survival and limits inflammation [29–33,41]; TIMP-1 limits inflammation, blood-brain barrier damage, and promotes OPC differentiation [46–50]; B2M may indicate microglia activation related to removal of myelin debris and limiting inflammation in the cuprizone lesions; soluble B2M in the MS CSF may indicate increased cellular metabolism and degradation in the CNS.