However, models of biomarker change in AD have been based mostly on cross-sectional data.6,9,10 More recently, many models have classified biomarkers according to their proposed association with the biological underpinnings of the disease; the recent amyloid/tau/neurodegeneration (A/T/N) framework11 was developed to provide a more biological rationale to the classification of the disease. This evidence concerns the gene MAPT and Alzheimer disease.