Satralizumab provides durable inhibition of IL-6 signaling (76) and is indicated for another autoantibody-mediated neuroimmunological disease, aquaporin-4 immunoglobulin G antibody-positive neuromyelitis optica spectrum disorder, as monotherapy or as an add-on to immunosuppressive therapy (IST) (75, 77–80). The gene discussed is AQP4; the disease is neuromyelitis optica.