IL6 and neuromyelitis optica: Elevated levels of IL-6 in the CNS have been found in inflammatory CNS diseases, such as idiopathic transverse myelitis [35], and neuromyelitis optica [36], cancer, and cysts [37,38] (median CSF IL-6 654.3 ± 247.9, 281, 22.87  ±  2.62, and 594.2  ±  191.8 pg/mL, respectively).