MAPT and Alzheimer disease: Notably, the plasma AD biomarkers such as amyloid beta (Aβ), glial fibrillary acidic protein (GFAP) (Lohman et al. 2024), neurofilament light chain (NfL) (Lohman et al. 2024), and phosphorylated tau (p‐tau) (Zhu et al. 2024) have been associated with APOE ε4‐related functional changes.