APOE and Alzheimer disease: The contribution of genetic variation at the 17q21.31 locus to AD biomarker detection has received less attention than APOE genotype; however, a recent GWAS meta-analysis revealed that the locus was significantly associated with plasma t-tau in European Americans but not in African Americans (Sarnowski et al., 2022), which is suggestive that genetic architecture related to ancestry may influence tau pathology.