In the past decades since the discovery of a linkage between tau and neurodegenerative disease, there has been intense focus on understanding the mechanisms and risk factors underlying aggregation and propagation of tau pathology in numerous neurodegenerative tauopathies such as AD, chronic traumatic encephalopathy (CTE), frontotemporal dementia (FTD), and progressive supranuclear palsy (PSP), among others. The gene discussed is MAPT; the disease is Alzheimer disease.