NEFL and Alzheimer disease: We dichotomized Aβ pathology based on the previously used cutoff points and included covariates, such as CSF p-tau and/or CSF Aβ42:p-Tau interaction that could potentially confound the association between NFL levels and grey matter density maps, and yet, we found correlations only in the Aβ positive groups and in the AD-vulnerable regions [34].