In summary, our results show that elevated baseline concentrations of NfL are associated with Aβ deposition, brain atrophy, brain connectome, glucose metabolism, and brain perfusion in AD signature regions, including the precuneus, lateral temporal cortex, inferior parietal cortex, amygdala, entorhinal gyrus, and hippocampus in aMCI patients. This evidence concerns the gene NEFL and Alzheimer disease.