AQP4 and neuromyelitis optica: Proof of concept for this hypothesis has been provided, for example, by antibodies against glucose-regulated protein 78 (GRP78) in addition to aquaporin 4 (AQP4) in patients with neuromyelitis optica spectrum disorder (NMOSD) (Shimizu et al., 2017) or antibodies against unconventional Myosin-X in NMDAR encephalitis (Li et al., 2023).