In the APOE ε4 intervention, lowering the prevalence of the APOE ε4 gene from the internal setting to the external setting decreased the prevalence of cognitive impairment from 70.0% to 63.1%, increased the mean of CSF-Aβ from 1076.6 to 1291.2 pg/ml and decreased the mean CSF-tau from 292.7 to 260.1 pg/ml. The gene discussed is APOE; the disease is Cognitive impairment.