Commonly used AD biomarkers include amyloid positron emission tomography scans (Chételat et al., 2020), cerebrospinal fluid amyloid and tau levels (Blennow and Zetterberg, 2018; Blennow et al., 2019), and plasma amyloid and tau concentrations (Hampel et al., 2018). This evidence concerns the gene MAPT and Alzheimer disease.