As has been described above for tau, several studies on intracerebral injections of Aβ-rich brain extracts either from AD mice or patients propose that Aβ aggregation can be initiated by prion-like seeding (Kane et al., 2000; Meyer-Luehmann et al., 2006; Eisele et al., 2009; Jucker and Walker, 2013; Ziegler-Waldkirch et al., 2018; Friesen and Meyer-Luehmann, 2019; Katzmarski et al., 2020). This evidence concerns the gene MAPT and Alzheimer disease.