Significant numbers of CD68+, HLA+ and complement anaphylatoxin receptor (C3a and C5a) positive cells are present in NAGM and NAWM of long-standing MS, showing that the normal-appearing tissue contains similar populations of activated microglia/macrophages but at lower densities than in focal lesions [2,23,25]. The gene discussed is CD68; the disease is myeloid sarcoma.