Apolipoprotein E (APOE) gene (ε2, ε3, and ε4 alleles) is highly associated with AD.1APOE ε4 allele is a well established genetic risk for decline of memory, ε3 allele plays a neutral role,1,2 whereas ε2 allele enhances neuroprotection against AD.3,4 Recent neuroimaging techniques, including functional magnetic resonance imaging (fMRI), allow for the investigation of genetic influence on the brain. Here, APOE is linked to Alzheimer disease.