Importantly, we and others have previously shown that the polySer containing protein SRRM2 is mislocalized to tau aggregates in tau transgenic mice as well as in corticobasal degeneration and Alzheimer’s disease patient tissue indicating conserved associations between polySer and tau.15,45 Future work investigating the mechanism driving polySer and tau associations will allow for fine-tuning of targeting functions and potential separation of the pro-pathogenic effects of polySer alone. This evidence concerns the gene MAPT and early-onset autosomal dominant Alzheimer disease.