Considering the 156 individuals (108 AD, 34 FTD, and 14 controls) with paired CSF/plasma samples, we found significant correlations between CSF and plasma levels for the Aß42/40 ratio (rho = 0.43, p < 0.001) and p-tau181 level (rho = 0.41, p < 0.001), but no significant correlations for Aß40, Aß42 and T-tau. This evidence concerns the gene MAPT and Alzheimer disease.