As amyloid, tau, and neurodegeneration (A/T/N) are all considered to be the defining biological characteristics of AD, a recent NIA-AA task force recommended (Jack et al., 2018; Revised Again: Alzheimer’s Diagnostic Criteria Get Another Makeover | ALZFORUM, 2023) that future AD research studies should measure these processes. This evidence concerns the gene MAPT and Alzheimer disease.