However, NfL was superior to t-tau in the discrimination between atypical prion disease and atypical/rapidly progressive AD (AUC 0.946 ± 0.021 vs. 0.654 ± 0.057), and the NfL/p-tau ratio was the best biomarker in terms of sensitivity and specificity in this differential diagnosis (AUC 0.989 ± 0.007) (see Additional file 1: Figure S3). This evidence concerns the gene MAPT and Alzheimer disease.