PET imaging of AD patients and healthy individuals of various ages and stages of disease reveals a synergistic association of co‐occurring Aβ, tau, and activated microglia with cognitive impairment, and its predictive ability was unmatched by co‐occurring Aβ and tau, suggesting the intersection of aberrant microglial activation and proteinopathy may be necessary for the evolution to clinical manifestations [22]. Here, MAPT is linked to proteostasis deficiencies.