For example, at the median age of 71 years, the prevalence estimates of tau positivity in the temporal cortex were higher in Aβ-positive APOE ε4 carriers compared with Aβ-positive APOE ε4 noncarriers in CU individuals (mean difference 8.4% (95% CI 3.0–13.8%), P < 0.001), individuals with MCI (mean difference 15.6% (95% CI 4.7–26.5%), P = 0.001) and those with dementia (mean difference 7.5% (95% CI 3.1–11.9%), P < 0.001). This evidence concerns the gene APOE and dementia.