Spinal nerve root enhancement or myeloradiculitis has been observed in a few patients with AQP4-IgG-positive NMOSD [47, 101, 102, 204, 211], but was recently reported also in MOG-EM/MOGAD [176, 202, 206, 217] and even in individual patients with (pediatric) MS [206]. The gene discussed is AQP4; the disease is myeloid sarcoma.