MAPT and tauopathy: In the present study, in order to investigate whether PTEN can affect the phosphorylation, aggregation and microtubule binding ability of mutant tau associated with tauopathy, we used an FTDP-17 missense mutant tau, R406W, which has been shown to be less soluble and less capable of binding to microtubules than wild-type tau [44,45].