AQP4 and neuromyelitis optica: For example, the CSF interleukin (IL)-6 levels in NMO patients were significantly higher compared to those in patients with MS or other non-inflammatory neurological disorders, and were significantly correlated with clinical variables, including the Expanded Disability Status Scale (EDSS) score, CSF glial fibrillary acidic protein (GFAP) level and anti-AQP4 antibody titers [15–17].