In the CSF of patients with prion diseases, abnormal concentrations of brain-derived proteins, such as 14-3-3 protein, tau protein, NfL (Neurofilament light chain), alpha- and beta-synuclein, GFAP, Aβ40/42 and many others are altered, probably because of the general process of rapid neurodegeneration [8]. The gene discussed is NEFL; the disease is prion disease.