It may be no coincidence then that hypercholesterolemia, which increases the risk of PCa [140], is associated with the APOE ε2 genotype [141], where the aforementioned use of statins, often used to treat hypercholesterolemia, is protective [125,126], high cholesterol seen in people with AD [142], where APOE ε4 is quite common might also be an important consideration to explore further. This evidence concerns the gene APOE and Alzheimer disease.