For instance, individuals carrying APOE4 allele often exhibit altered levels of certain plasma biomarkers associated with AD, particularly amyloid-beta (Aβ) peptides [3], with higher doses of APOE4 generally correlating with lower plasma Αβ42/Aβ40 levels, indicating increased amyloid plaque deposition in the brain [4]. This evidence concerns the gene APOE and Alzheimer disease.