While the mechanisms linking APOE4 to AD are unclear, it is likely that APOE4 increases the risk of AD by promoting neurotoxicity and/or being less neuroprotective than proteins produced by the other APOE alleles, APOE2 or APOE3 (Corder et al., 1994; Kim et al., 2009; Liu et al., 2013; Raulin et al., 2022). The gene discussed is APOE; the disease is Alzheimer disease.