Group B (PSA/risk stratification/biopsy) consists of Göteborg-2 [7,20], Prostate Cancer Early Detection Study Based on a “Baseline” PSA value in Young Men (PROBASE) [21], Organised Prostate cancer Testing (OPT) [22,23], STHLM3-MRI [24,25], ProScreen [26,27], and BARCODE1 [28,29]. Here, KLK3 is linked to prostate carcinoma.