Elevated peripheral GFAP and NfL levels can also be observed in other conditions, including traumatic brain disorders, neurodegenerative disorders (e.g., Parkinson disease and amyotrophic lateral sclerosis), and autoimmune disorders of the CNS (e.g., multiple sclerosis) [14, 19]. The gene discussed is GFAP; the disease is amyotrophic lateral sclerosis.