APOE4 homozygotes are resistant to the mnemonic benefits of 17β-estradiol in the EFAD mouse model of Alzheimer's disease.

The significant benefit of E only in E3FAD and E3/4FAD mice suggests that having two copies of the APOE4 allele results in lower susceptibility to the memory-enhancing effects of E in the EFAD model. These findings provide novel evidence that E may be of clinical benefit to APOE3 and APOE3/4, but not homozygous APOE4, carriers.