GFAP and Alzheimer disease: Prior studies suggested that neurofilament light (NfL) and GFAP remained elevated for at least 5 years after TBI compared to individuals without TBI,3, 4 whereas studies investigating trajectories of AD‐related biomarkers (amyloid beta [Aβ] and tau protein isoforms) have generally had shorter‐term follow‐up and more heterogeneous results.3, 5, 6