KLK3 and cancer: When analysing individual biopsy cores to avoid higher grade cancer masking lower grade cancer, PSA was not significantly associated with the risk of ISUP 1 cancer (Fig 1B) for three of the four PSA groups, with odds ratios ranging from 0.91 (95%CI: 0.83–1.00) for PSA level 3 to 4 ng/mL, 1.05 (95%CI: 0.96–1.16) for PSA level 4 to 6 ng/mL, 1.21 (95%CI: 1.08–1.36) for PSA level 6 to 10 ng/mL and 1.11 (95%CI: 0.92–1.35) for PSA level 10 to 15 ng/mL compared to men with PSA from 2 to 3 ng/mL.