NfL has been proposed as a sensitive diagnostic or prognostic marker for various neurodegenerative diseases, including PD, Alzheimer’s disease (AD), spinocerebellar ataxia type 3 (SCA3), amyotrophic lateral sclerosis (ALS) and Huntington’s disease (HD) [66–70]. The gene discussed is NEFL; the disease is amyotrophic lateral sclerosis.