In this study, we compared the performance of MTBR-tau243 to other CSF phosphorylated tau measures, including p-tau181, p-tau205, p-tau217 and p-tau231 phosphorylation occupancies (% p-tau to total tau ratio), which are also reported as biomarkers to recapitulate AD pathologies21,29 and we showed that MTBR-tau243 was the fluid biomarker most strongly associated with tau-PET. Here, MAPT is linked to Alzheimer disease.