We further investigated the moderating effects of apolipoprotein E ε4 (APOE4) on the relationship between CA and AD-related brain changes, as CA is particularly protective in APOE4 carriers for the risk of dementia onset (Carlson et al., 2008) and Aβ accumulation (Wirth et al., 2014; Vemuri et al., 2016). This evidence concerns the gene APOE and Alzheimer disease.