The combination of the PI-RADS score and PSAD (AUC = 0.80) demonstrated a significantly superior performance compared to both PSA (AUC = 0.75, p < 0.01) and the Prostate Cancer Prevention Trial (PCPT) risk calculator (AUC = 0.76, p < 0.01). The gene discussed is KLK3; the disease is prostate cancer.