Amyloid-β (Aβ) and tau aggregation-associated neurodegeneration might start decades before the actual manifestation of AD symptoms, whose presence could be recognized as the AD continuum according to the biological definition of AD based on the ATN (Aβ deposition [A], pathologic tau [T], and neurodegeneration [N]) hallmarks (7, 8). This evidence concerns the gene MAPT and Alzheimer disease.