MAPT and Alzheimer disease: Similarly to the findings in the whole CAA group, the tau(‐) CAA subgroup had significantly lower p‐tau 217, p‐tau 217/t‐tau, p‐tau 217/Aβ40, and p‐tau 217/Aβ42 compared to the AD group (all p < 0.05) and comparable plasma Aβ40, Aβ42, and Aβ42/40 ratio (Table S1).