MAPT and neurodegenerative disease: The A/T classification resulted in four groups of individuals: 352 A−T− (Aβ and tau negative without a neurodegenerative disease diagnosis), 184 A+T− (Aβ positive, tau negative), 231 A+T+ (Aβ and tau positive) and 110 non-AD (Aβ-negative patients with clinically diagnosed non-AD neurodegenerative diseases) (Table 1 and Extended Data Table 1).