The important neuroinflammation present in the dentate gyrus of 5XFAD mice injected with PHF-tau proteins could be responsible for the increased amyloid plaque burden in this area, since microglial cells have been suggested to be involved in the production of amyloid-β (Wegiel and Wisniewski, 1990; Baik et al., 2016; Spangenberg et al., 2019) and could thus be directly responsible for the increased amyloid burden observed in AD injected 5XFAD mice. This evidence concerns the gene MAPT and Alzheimer disease.