However, because it remains challenging to confidently diagnose sporadic tauopathy in vivo, familial tauopathy (identified via the presence of pathogenic MAPT variants in individuals with a family history of neurodegenerative disease) represents a powerful lens through which we can not only elucidate the pathophysiologic processes underlying hereditary tauopathy but also uncover shared processes that may contribute to sporadic tauopathy. Here, MAPT is linked to neurodegenerative disease.