Alzheimer disease (AD) is the sixth leading cause of death in the US, but existing treatments provide only a modest improvement in symptoms. To our knowledge, no approved treatment exists that improves the course of disease or underlying pathology. Research on disease-modifying AD treatments has proven to be extremely challenging, with a number of major recent clinical trials of drug therapies resulting in negative or ambivalent findings.1,2 While many alternative ideas for developing a treatment for AD are being pursued, 2 key strategies have emerged: initiating interventions earlier in the course of disease in individuals who are at risk but unimpaired and identifying targets beyond abnormal amyloid and tau proteins, the pathology that defines AD.