Serum PSA-Gi levels in the both total PSA range ≤20 ng/mL (Figure 3a,b) and ≤10 ng/mL (Figure 3d,e) were significantly higher in patients with PCa (median: 0.1680 U/mL and median: 0.1140 U/mL, respectively) than in patients with BPH (median: 0.0715 U/mL and median: 0.0670 U/mL, respectively), p < 0.0001. Here, KLK3 is linked to benign prostatic hyperplasia.