Recent developments in fluid and imaging biomarkers that reflect the key pathological hallmarks of Alzheimer's disease (AD)—deposits of extracellular amyloid‐β (Aβ) and intracellular tau proteins—have transformed the perception of the disease in living individuals from a clinical syndrome to a biological continuum that begins prior to the onset of symptoms (Scheltens et al., 2021). The gene discussed is MAPT; the disease is Alzheimer disease.