Using antibodies against phospho-tau epitopes that are distributed in the PRR and C terminal region which were previously identified to be over-represented in AD (Fig. 3a; AT270, AT100, AT180, PHF1, pSer422 and AT8), we found that PSP-tau seeded Variant 4 showed robust phosphorylation on these sites and was identical to P301L tau (Fig. 3b). This evidence concerns the gene MAPT and Alzheimer disease.