Currently, the D’Amico risk classification, EAU-EanM-Estro-Esur-SIOG Guidelines on Prostate Cancer, and National Comprehensive Cancer Network (NCCN) Guidelines for Prostate Cancer are commonly used for risk classification, and the main parameters evaluated include pretreatment prostate-specific antigen (PSA) level, Gleason score (GS), and clinical T stage (3–5). The gene discussed is KLK3; the disease is prostate cancer.