Alterations in NfL levels have been studied, for example, as a biomarker in neurodegenerative diseases such as Alzheimer’s disease (AD), amyotrophic lateral sclerosis (ALS) and frontotemporal dementia, and other disorders such as stroke, CNS tumors and neuropathies [5,8,30]. The gene discussed is NEFL; the disease is early-onset autosomal dominant Alzheimer disease.