Concerning the ApoE4 variant, regardless of AD diagnosis, older adults that are ApoE4+ display a greater level of Aβ accumulation that is not evident in ApoE3+ or ApoE2+ individuals (Lim et al., 2017), and AD patients with the ApoE4 genotype (+/+ or +/−) display higher levels of intraneuronal Aβ accumulation compared to controls, indicating a baseline detrimental cognitive effect (Yamazaki et al., 2019). The gene discussed is APOE; the disease is Alzheimer disease.