Although traditional biomarkers, such as neurofilament light chain (NfL), Aβ42, and phosphorylated tau (p-Tau181), have been valuable in monitoring disease progression, their ability to detect early changes in brain aging and distinguish between normal aging and neurodegenerative disease is limited (Higgins-Chen et al., 2021; Basisty et al., 2020). Here, NEFL is linked to neurodegenerative disease.