IL1B and myeloid sarcoma: These differences in IL-1β expression were not a feature of lesion sites (in spinal cords/medullas of NMO patients vs. brains of MS patients), because IL-1β expression was essentially absent in initial/active spinal cord and medullary lesions of MS cases 10 and 11, and in late/active lesions in the spinal cords and optic chiasm of patients with progressive MS (cases 12–17) (Table2).