Its expression, like with NfL, has also been detected in other diseases, such as neuromyelitis optica [199] and Alzheimer’s disease [200]; therefore, it would not be suitable as a standalone biomarker but rather one that can be used alongside MRI to assess microstructural changes and diagnose the ongoing neurodegeneration of MS in patients. Here, NEFL is linked to early-onset autosomal dominant Alzheimer disease.