An AD-RAI > 0.5 was associated with an increased risk of AD conversion in both the APOE-ε4 + group (AD-RAI > 0.5, median survival time = 24 months; AD-RAI < 0.5, median survival time = 96 months; P < 0.001) and APOE-ε4- group (AD-RAI > 0.5, median survival time = 96 months; AD-RAI < 0.5, median survival time > 180 months; P < 0.001). The gene discussed is APOE; the disease is Alzheimer disease.