To discriminate between AD and CN subjects, the area under the curve (AUC) for plasma angiostatin was 0.6639 (p = 0.0081, 95% CI = 0.5491–0.7787), which was slightly higher than 0.6253 (p = 0.0568, 95% CI = 0.4938–0.7569) for plasma Aβ40 and lower than 0.6877 (p = 0.0043, 95% CI = 0.5610–0.8143) for plasma Aβ42 and 0.6770 (p = 0.0235, 95% CI = 0.5273–0.8267) for CSF Aβ40. This evidence concerns the gene PLG and Alzheimer disease.