Increased NFL in CSF was also associated with several neurologic conditions, including Alzheimer’s disease, amyotrophic lateral sclerosis, multiple sclerosis, inherited neuropathy, Parkinson’s disease, dementia, multiple system atrophy, and progressive supranuclear palsy, also predicting the prognosis of Alzheimer’s and Parkinson’s diseases [16–19]. This evidence concerns the gene NEFL and Parkinson disease.