Most of the 2173 clinical trials for AD performed before 2019 involved drug candidates designed to hit one target that seems to play a prominent role in AD pathogenesis, such as β-amyloid biology (22%), tau pathology (12%), mitochondrial dysfunction (17%), neurovascular mechanisms (8%), or neuroinflammation (5%), among others, while 19% were to address neurotransmitter deficits [10]. Here, MAPT is linked to Alzheimer disease.