MAPT and Alzheimer disease: For instance, recent findings in AD link distinct tau conformers to a more rapid disease progression in AD [40] and post-translational modification to different disease stages of AD [76], and specific tau filament folds observed with cryo-electron microscopy have been associated with specific classes of sporadic tauopathies [16, 62, 86], laying the foundation for a structure-based classification of 3R and 4R tauopathies.