In the brain datasets, compared to controls, AD patients were significantly older (mean ± SD for AD: 86.5 ± 6.0 years and controls: 84.8 ± 7.4 years; two sample t-test, P < 0.001), more likely to be APOE ε4 carriers (AD: 38% carriers vs controls: 15% carriers; Chi-squared test, P < 0.001), and more likely to be females (AD: 65% female vs controls: 51% female; Chi-squared test, P < 0.001). The gene discussed is APOE; the disease is Alzheimer disease.