These results are consistent with our earlier studies comparing different forms of tau in CSF from controls and AD patients [20], i.e., tau detected by mid-region assays account for the highest levels of tau in AD CSF, NT1-tau detects comparable but lower amounts of tau than MR assays, and FL-tau, although elevated in AD, accounts for only a fraction of the tau detected by the other two tau assays. This evidence concerns the gene MAPT and Alzheimer disease.