The STRING interaction analysis (Figure 5a) revealed that the components of the EV proteomic signature detected in the urine of prostate cancer cases were enriched in their interactions (PPI enrichment, p = 0.032) with the highest confidence (0.9), forming four potential PPI modules consisting of 17 nodes and 18 edges: SERPINA3-LRG1-GIG25-CP-MRPL13-PRL3, LILRB2-LILRB4-HLA-B-LILRB1, PDIA4-ERO1LB-ERP29-UBLCP1, and AMY2A-AMY2B. This evidence concerns the gene HLA-B and Familial prostate cancer.