MAPT and Alzheimer disease: Although further research is necessary to thoroughly investigate the role of pathological tau formation in the marmoset and the trajectory of tau neurotoxicity that leads to neurodegenerative diseases, taken together, these findings highlight the importance of the marmoset as a model system for studying primate‐specific mechanisms of AD and tauopathies, as well as the benefit of the marmoset for evaluating interventions aimed at stopping or preventing AD.