Interestingly, only one of the proteins that was increased in MCI-progressors versus MCI-stable groups, NF-L, was also differentially expressed in Dem-Alzheimer's disease versus CN participants, indicating that prognostic biomarkers of progression from MCI to dementia due to probable Alzheimer's disease are not necessarily diagnostic biomarkers for dementia due to probable Alzheimer's disease. This evidence concerns the gene NEFL and Alzheimer disease.