miR-375 was significantly downregulated in 83.5% of patients compared to BPH controls and showed stronger diagnostic accuracy (AUC = 0.81, 95% CI: 0.70–0.92, p = 0.00016) compared with PSA (AUC = 0.71, 95% CI: 0.56–0.86, p = 0.013). Here, KLK3 is linked to benign prostatic hyperplasia.