MAPT and Alzheimer disease: In vivo and postmortem comparative studies using different tau tracers indicated even more divergent patterns among tracers in primary tauopathies than in AD (Ono et al., 2017; Schonhaut et al., 2017; Chen et al., 2018; Endo et al., 2019; Ikeda et al., 2019; Leuzy et al., 2019; Arakhamia et al., 2020; Brendel et al., 2020; Tagai et al., 2020; Yap et al., 2021).