APOE and Alzheimer disease: Here we aimed at exploring the impact of sex and ApoE ε4 genotype in the AD spectrum on longitudinal measures of the basal forebrain and hippocampus, as a comparison region.<h4>Methods</h4>We leveraged the German multi-centered study DELCODE and analyzed 712 individuals (median age: 71.25 years, interquartile range [IQR] = 9.22) with follow-up MRI scans (median time: 2.8 years, [IQR] = 1.75).