KLK3 and Familial prostate cancer: There were no substantial differences in baseline characteristics between men with high-risk prostate cancer and no/low-risk prostate cancer other than mean age (62.4 years vs. 59.3 years, p ≤ 0.001) and mean PSA level (5.5 vs. 1.3 ng/mL, p ≤ 0.001) (Table S1).