NEFL and Alzheimer disease: Alemany et al. [121] conducted a study with 156 cognitively unimpaired adults at higher risk for AD from the ALFA+ study, examining the relationship between air pollution and AD biomarkers, including CSF levels of Aβ42, Aβ40, p-tau, t-tau, neurofilament light chain (NfL), and cerebral amyloid load.