Studies in African-ancestry cohorts consistently reported significant association between ApoE ε4 homozygosity and AD, but showed inconsistent results for ε4 heterozygote allele individuals (ε3/ε4 OR:1.1–2.2; ε4/ε4 OR: 2.2–5.7) [6,8–13]. The gene discussed is APOE; the disease is Alzheimer disease.