In the study by van Bergen et al., cognitive-impaired subjects with the apolipoprotein E ε4 (APOE-e4) allele presented with higher iron and amyloid-β plaque-loads in the subcortical and cortical regions of the brain and greater risk for neurocognitive dysfunction owing to Alzheimer’s disease [417]. This evidence concerns the gene APOE and early-onset autosomal dominant Alzheimer disease.