Although neurofilaments are elevated across neurodegenerative disease, the CSF and plasma levels of NfL and the phosphorylated neurofilament heavy chain (p-NfH) are highest in ALS compared to healthy controls, neurodegenerative disorders such as AD, FTD, and corticobasal syndrome (CBS), and other motor-nerve disorders [47,48]. This evidence concerns the gene NEFL and Alzheimer disease.