Studies have shown that Aβ1–42, total tau protein, and threonine 181 phosphorylated tau protein (p-tau) (Asher and Priefer, 2022; Ossenkoppele et al., 2022) show very consistent changes in AD dementia and prodromal AD, and they have been included in the diagnostic criteria for AD studies and as evidence of the presence of AD pathology (Dubois et al., 2014). This evidence concerns the gene MAPT and Alzheimer disease.