Furthermore, GFAP is recognized as a marker for MS severity (Abdelhak et al., 2018; Högel et al., 2018; Abdelhak et al., 2019; Barro et al., 2023) and blood GFAP could be a promising biomarker to distinguish between classic autoimmune inflammatory astrocytopathy, neuromyelitis optica spectrum disorders (NMOSD) and MS (Storoni et al., 2012; Kim et al., 2022). Here, GFAP is linked to neuromyelitis optica.