APOE and Alzheimer disease: There were weak to moderate correlations between total apoE and AD biomarkers for all individuals (rho = − 0.14 for Aβ42/40, rho = 0.41 for t-tau, rho = 0.35 for p-tau, p < 0.001) (Additional file 8: Figure S7A), for the Aβ+ group separately (rho = − 0.15 for Aβ42/40, rho = 0.41 for t-tau, rho = 0.28 for p-tau, p < 0.001) (Additional file 8: Figure S7B) and for the Aβ− group (rho = − 0.11 for Aβ42/40, rho = 0.52 for t-tau, rho = 0.54 for p-tau, p ≤ 0.001) (Additional file 8: Figure S7C).