GFAP and amyotrophic lateral sclerosis: In addition to the classical fluid-based biomarkers of neurodegeneration such as Aβ42 and Tau, markers of neuronal health and astrogliosis such as Ubiquitin C-Terminal hydroxylase (UCH-L1) and glial fibrillary acidic protein (GFAP) are also seen to be increased in neurodegenerative disorders such as Alzheimer’s disease, ALS, and frontotemporal dementia [45,46,47,48].