Anti-MBP antibodies have been detected not only in sera, but also in the cerebrospinal fluid (CSF) (Warren et al., 1995; Sellebjerg et al., 2000) in 85% relapsing-remitting MS patients and 45% MS patients, respectively, compared to 2% in non-MS controls. The gene discussed is MBP; the disease is myeloid sarcoma.