Inebilizumab, a humanized mAb targeting CD19, received FDA approval for the treatment of neuromyelitis optica spectrum disorder (NMOSD) in adult patients who are seropositive for immunoglobulin G autoantibodies against aquaporin-4 (AQP4-IgG) in June 2020 [50]. This evidence concerns the gene CD19 and neuromyelitis optica.