The lack of efficacy might be explained by the fact that the amount of CSF tau did not change between the control subjects and PSP patients (Sandusky-Beltran and Sigurdsson, 2020) and that IPN002 did not reduce amounts of intracellular free tau in cultured cells (Bright et al., 2015). Here, MAPT is linked to supranuclear palsy, progressive, 1.