AQP4 and myeloid sarcoma: In the context of clinical trials, a phase 1b study included eight patients with MS and four patients with neuromyelitis optica spectrum disorders (NMOSD), a chronic brain and spinal cord disorder primarily associated with aquaporin-4 (AQP4) autoantigens that target up to 80% of cases (all patients in this study had anti-AQP4 antibodies as an enrollment criterion).