CSF NFL showed a high discriminatory value for differentiating between PD and control subjects, so its levels may be helpful in the differential diagnosis between PD and healthy subjects, especially when used with other CSF biomarkers (Parnetti et al., 2013; Oosterveld et al., 2020), as, used alone, it reflects only one pathological process present in PD. The gene discussed is NEFL; the disease is Parkinson disease.