Glial fibrillary acidic protein (GFAP) is an intracellular protein of the astrocytic cytoskeleton, and increases in central nervous system (CNS) GFAP and circulating GFAP levels have been described in the context of traumatic brain injury (TBI)11, in the context of neurodegeneration in AD12 as well as in chronic neuroinflammatory conditions such as multiple sclerosis (MS)13. Here, GFAP is linked to multiple sclerosis.