AQP4 and brain neoplasm: Numerous case reports have underscored the diagnostic challenges and occasional clinical overlap between NMOSD and gliomas, primarily due to the risk of misdiagnosis in which often NMOSD is erroneously identified as brain tumors located in regions where AQP4 is abundantly expressed (Park and Hwang, 2021; Song et al., 2020; Tomari et al., 2024; Natsis et al., 2021).