CD9 and benign prostatic hyperplasia: Additionally, in patients with PSA gray zone (4–10 ng/ml) including 23 PCa and 31 BPH, the model based on uEVEpCAM-CD9 showed a better diagnostic performance (AUC = 0.917, P < 0.0001) than the uEVEpCAM-CD9 only (AUC = 0.887, P < 0.0001) and the traditional biomarkers PSA (AUC = 0.712, P = 0.0018) (Figure 4E).