Based on the view that pDMN vulnerability to Aβ arises from its role as a large-scale connectivity hub (Buckner et al., 2009, de Haan et al., 2012), we asked whether young adults at heightened genetic risk for AD (via presence of the APOE-ε4 allele) would show increased pDMN structural connectivity (Greicius et al., 2009). This evidence concerns the gene APOE and Alzheimer disease.