The AUC values for the combined plasma marker NFL/Aβ42 were higher than those for NFL or Aβ42 alone, suggesting that NFfL/Aβ42 may serve as a very reliable biomarker for the early diagnosis and monitoring of AD disease development and could be used as an initial screening tool for AD and in subsequent research on the illness’s potential treatment. This evidence concerns the gene NEFL and Alzheimer disease.