MAPT and Alzheimer disease: When grouping the subjects into three hypothetical “disease stages” (Fig 6), we found no correlations between plasma P‐tau217 and either Aβ PET or tau PET in those that were negative for both Aβ and tau PET (we consider these individuals to not have AD), significant correlations to Aβ PET (but not tau PET) in those who were within the positive range for Aβ PET only (we consider this an early stage of AD), and significant correlations to both Aβ PET and tau PET (but strongest with tau PET) in those who were positive for both Aβ and tau PET (we consider this a later stage of AD).