The AUC values distinguishing participants with preclinical AD from CN Aβ- participants were 0.668 for plasma NFL concentrations (cut-off value > 17.3) and 0.741 for plasma Aβ1–42 concentrations (cut-off value < 10.45), whereas the AUC value for plasma NFL/Aβ1–42 increased to 0.791 (cut-off value > 1.7). This evidence concerns the gene NEFL and Alzheimer disease.