The AUC of LDN-PSAD (obtained from ROC curve) has been shown to be superior to that of LDN-PSA and PSAD alone in different studies, namely 0.86 vs. 0.83 and 0.81, respectively [125] and 0.85 vs. 0.78 and 0.84, respectively [23] and could also be used successfully for distinguishing the PCa from the BPH cohort and detection of castration-resistant PCa (AUC = 0.90) [126], while the AUC of tPSA was in the range of 0.59 to 0.71. Here, KLK3 is linked to benign prostatic hyperplasia.