In this context, specific cut-off levels for blood NfL were shown to discriminate patients with some neurological conditions (i.e., PD, FTD) from patients with PPD (area under the curve [AUC] = 0.70–0.85), thus supporting the clinical application of NfL measure in the context of the differential diagnosis of dementia [27]. This evidence concerns the gene NEFL and Parkinson disease.