More recently, in aquaporin-4 (AQP4) positive neuromyelitis optica spectrum disorder (NMOSD), the anti-CD19 antibody inebilizumab [10] as well as the IL6-receptor blocking agent satralizumab [11], which interferes with B-cell activation, have demonstrated efficacy. The gene discussed is AQP4; the disease is neuromyelitis optica.