AD-based biomarkers such as Aß-PET, CSF amyloid ß42 and phosphorylated tau, or plasma phosphorylated tau in studies of patients with previous repetitive head impacts and TES may add to more specific biomarker signatures that are specific to CTE and minimize the risk of misattributing biomarker changes to AD (co)pathology. This evidence concerns the gene MAPT and Alzheimer disease.