Increased CSF NfL concentrations have been reported in multiple sclerosis (MS) [6], subcortical vascular dementia [7], Alzheimer’s disease (AD) [5], frontotemporal dementia (FTD) [8], Creutzfeldt-Jakob disease (CJD) [9], atypical parkinsonisms [10], normal pressure hydrocephalus [11], amyotrophic lateral sclerosis (ALS) [12], CNS infections [13], and brain traumatic injury [14]. The gene discussed is NEFL; the disease is myeloid sarcoma.