PLG and Alzheimer disease: Then, we analysed the diagnostic value of angiostatin in distinguishing AD patients with APOE-ε4 from CN subjects, and the AUC for plasma angiostatin increased to 0.7321 (p = 0.0011, 95% CI = 0.6102–0.8541), which was still higher than that for the plasma biomarker Aβ40 (AUC = 0.6261) but still lower than that for Aβ42 (AUC = 0.7453) (Fig. 4B).