Neuroimaging and fluid biomarkers of Alzheimer’s disease pathology, including amyloid and tau PET and cerebrospinal fluid (CSF) and plasma assays for Aβ40, Aβ42 fragments and phospho-tau (p-tau) species (e.g. p-tau181, p-tau217, and p-tau231) have played a critical role in understanding and characterizing the natural history of disease pathology and advancing clinical trials for disease modifying therapies. Here, MAPT is linked to early-onset autosomal dominant Alzheimer disease.