Interestingly, there was a significant decrease in phosphorylated tau species in subcortical white matter tissue in the AD, C9ORF72, MAPT, and GRN pathology groups (Fig. 2A) but a significant increase of phosphorylated tau species in cortical layers II-V and cortical layer I of the cortex in AD and MAPT tissue, as compared to neurologically healthy control (NHC) (Fig. 2B, C). Here, MAPT is linked to Alzheimer disease.