Multiple sclerosis (first of two parts).
D006801:Humans; D007962:Leukocytes / Q000276:immunology; D008214:Lymphocytes / Q000276:immunology; D008285:Major Histocompatibility Complex; D009103:Multiple Sclerosis / Q000097:blood / Q000134:cerebrospinal fluid / Q000175:diagnosis / Q000276:immunology / Q000473:pathology