The present analysis sought to follow the demonstrated importance of looking at sex in AD by evaluating sex differences in the functional connectivity between left prefrontal cortex and aDMN and pDMN, and between aDMN and pDMN, in individuals with normal cognition (NC) and early mild cognitive impairment (eMCI), who were participants in a large, national study of AD (the Alzheimer's Disease Neuroimaging Initiative or ADNI) and either had or did not have known AD risk factors (i.e., APOE ε4 allele) and pathological burden (i.e., positive amyloid PET). This evidence concerns the gene APOE and Alzheimer disease.