“…Production of IL‐6 is upregulated in many chronic neuroinflammatory diseases (reviewed in (Rothaug, Becker‐Pauly, & Rose‐John, ; Spooren et al, )). For example, it is found at elevated levels in the CSF of patients with neuromyelitis optica (NMO; Uzawa et al, ; Uzawa et al, ), transverse myelitis (TM; Dixit et al, ; Kaplin et al, ; Wullschleger et al, ), acute disseminated encephalomyelitis (ADEM; Ishizu et al, ), ALS (Sekizawa et al, ), herpes simplex encephalitis (Aurelius, Andersson, Forsgren, Skoldenberg, & Strannegard, ; Kamei et al, ), Parkinson's disease (PD; Muller, Blum‐Degen, Przuntek, & Kuhn, ), traumatic brain injury (TBI; Kumar, Rubin, Berger, Kochanek, & Wagner, ), stroke (Tarkowski et al, ), and other diseases. Interestingly, there is strong evidence for a primary, causal role of IL‐6 in the pathogenesis of neuromyelitis optica spectrum disorders (NMOSD), such as NMO (Araki et al, ; Uzawa, Mori, Arai, et al, ) and TM (Dixit et al, ; Kaplin et al, ), which we will discuss in more detail here.…”