Beyond papers describing CSF NfL as a reliable marker of neurodegeneration [53,54], serum NfL levels have been found elevated in AD [28,36,37,55,56,57,58,59,60], vascular dementia [61], Parkinson’s disease dementia [56] and FTD [37,40,62] when compared to healthy controls. The gene discussed is NEFL; the disease is dementia.