These additional AD biomarkers need to be studied longitudinally in different populations, through different stages of the disease, as these markers seem to be presenting a more nuanced and complex sequence of events in AD than the clinically established biomarkers Aβ42, t-tau, and p-tau which show a robust and predictable signal in all stages of FAD and sporadic AD. The gene discussed is MAPT; the disease is familial Alzheimer disease.