CXCR4 and myeloid sarcoma: Numerous studies have reported the expression of the CXCR4 and CXCR7 receptors by NSCs, OPCs, and NPCs, and the functional responses to activation by their only ligand, CXCL12, during development [48] and in inflamed adult CNS, particularly in MS/EAE [7, 8, 11, 22, 49].