As soluble Aβ oligomers result in neuronal toxicity via multiple pathways, several potential biomarkers, such as amyloid, tau, neurofilament light chain protein (NfL), neurogranin, neuroglial markers, and inflammatory cytokines [13,14,15], can be used to interrogate the contribution of these pathways to AD progression (Figure 3). This evidence concerns the gene NEFL and Alzheimer disease.