NEFL and Alzheimer disease: Plasma beta-amyloid 42 (Aβ42), beta-amyloid 40 (Aβ40), total tau protein (Tau), phosphorylated tau 181 (p-Tau181), neurofilament light chain (NfL), and glial fibrillary acidic protein (GFAP) are considered alternative approaches to confirm the biological pathogenesis of AD [41, 42].