This recommendation is supported by a placebo-controlled randomized trial, called “A multi-center, randomized, double-blind, placebo-controlled trial to determine the efficacy of rituximab against a relapse of neuromyelitis optica spectrum disorders with anti-aquaporin 4 antibody” (RIN-1),46which enrolled 38 adults with AQP4-IgG-positive NMOSD, randomized 1:1 to receive rituximab (375 mg/m2weekly for 4 weeks, followed by 2 g every 6 months) or placebo. Here, AQP4 is linked to neuromyelitis optica.