Tau PET was strongly associated with cognitive status in amyloid PET-positive individuals and its prominence in this model is highly consistent with previous literature.58,59 Although typically thought to reflect early disease changes, our models suggest CSF t-tau/Aβ40lumi, p-tau/Aβ40lumi and pT217/T217 reflect a degree of increasing disease severity at least through the early stages of cognitive impairment and reflect and intermediate process between early amyloidosis and the formation of NFTs. This evidence concerns the gene MAPT and Neurofibrillary tangles.