AQP4 and neuromyelitis optica: This suggests plasma cell targeting is an option also for the treatment of neuroinflammatory diseases such as neuromyelitis optica (NMO), which is clearly associated with autoantibodies specific for the water channel protein aquaporin 4 (AQP4), as well as with antibodies against myelin oligodendrocyte protein (MOG) in a subset of patients (89).