MAPT and Alzheimer disease: The significant association of plasma p-tau217 with longitudinal tau PET at this stage, coupled with continued associations with tau PET in AD dementia, suggest that the disruption of soluble tau, as reflected by elevated plasma p-tau217 levels, may roughly parallel tau accumulation across the symptomatic course of AD.69,71 Although we were not able to assess other p-tau variants such as p-tau231,72 we observed very similar results between p-tau181 and p-tau217, consistent with recent work showing that both variants perform similarly when differentiating individuals based on tau PET status.73