Two patients with myelitis (2/4, 50%) were NMO-IgG/anti-AQP4 positive; the first had Neuromyelitis Optica (NMO) [30], while the other had Longitudinal Extensive Transverse Myelitis (LETM), which belongs to the NMO spectrum of disorders [31]. Here, AQP4 is linked to neuromyelitis optica.