APOE and Alzheimer disease: Specifically, compared to ApoE3 and ApoE4, the higher expression of sialic acid in ApoE2 may contribute to the less potent interaction between ApoE2 and Aβ, ultimately, the slower rate of brain Aβ deposition, a mechanism thought to underlie ApoE2-mediated decreased risk for AD (Moon et al., 2022).