Several studies show that plasma p-tau217 is not increased in non-Alzheimer’s disease neurodegenerative diseases.16 Importantly, some of these diseases—such as frontotemporal dementia, progressive supranuclear palsy and corticobasal degeneration—are tauopathies that are known to show accumulation of p-tau at autopsy,24 but whether the amounts of NFTs are similar to those in Alzheimer’s disease is unknown. The gene discussed is MAPT; the disease is early-onset autosomal dominant Alzheimer disease.