Using PET scans from 1,612 participants covering the full clinical AD spectrum, tau was found to spread in four distinct spatiotemporal trajectories, including the limbic-predominant and medial temporal lobe (MTL)-sparing patterns as well as the posterior and lateral temporal patterns (Murray et al., 2011; Whitwell et al., 2012; Ferreira et al., 2020; Ossenkoppele et al., 2020; Vogel et al., 2021) (Figure 2). This evidence concerns the gene MAPT and Alzheimer disease.