KLK3 and neoplasm: Figure 3A shows that PSA levels significantly correlated with tumour progression (ANOVA, P=0.0027); however, in contrast to S1P, PSA was rather a late than an early marker gaining significance only during progression from stage 3 to stage 4 (27.15±12.67 vs 278.50±117.92, respectively, P=0.0463). Prostate-specific antigen was not a significant predictor of Gleason sum (Figure 3B, ANOVA, P=0.4282), but was however significantly elevated in patients with metastatic PCa (Figure 3C, 8.73±2.00 (negative) vs 323.20±127.8 (positive), P<0.0001).