In our cohort, 55% of all participants with MCI had a positive amyloid scan, and therefore, according to the recently revised research criteria for a biological definition of AD, fall within the trajectory of the AD continuum.31 Although their “T” (aggregated tau) status is unknown, they are “A” (amyloid) positive and “N” (neurodegeneration) positive as a group, based on the ATN classification. The gene discussed is MAPT; the disease is Alzheimer disease.