CSF NF-L has also been shown to increase in axonal degenerative disease such as Alzheimer’s disease (AD), multiple sclerosis (MS) and amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD)8, 34, 35, 36, 37, 38. This evidence concerns the gene NEFL and early-onset autosomal dominant Alzheimer disease.