MAPT and tauopathy: The specificity was quite remarkable as e2 is protective against mixed 3R and 4R species of tau in AD, but not predominantly 3R or 4R tau in various FTLD and tauopathies (e.g., 3R in Picks and 4R in PSP) (albeit the latter tauopathies may have specific cell type predilection or morphology that set them apart from AD tau species).