NEFL and Alzheimer disease: Indeed, several research groups have investigated blood measures of Aβ pathology (Aβ42/Aβ40, Aβ42, and Aβ40), tau deposition (phosphorylated tau181 (p-tau181)), neurodegeneration (neurofilament light (NfL)), and glial activation (glial fibrillary acid protein (GFAP)), and discovered important clues for AD diagnosing, screening and monitoring [1, 9–18].