Here, we aimed to compare two commercially available plasma p-tau217 immunoassays that differ in regard to their target specificity: the assay from ALZpath, targeting a single phosphorylation site (with minor p-tau181 and p-tau231 cross-reactivity),17 and the p-tau217 assay from Janssen (p-tau217+, additionally targeting p-tau212 and p-tau214)18 in individuals evaluated by dementia specialists and assessed with amyloid and tau PET. The gene discussed is MAPT; the disease is dementia.