It was also found that TRT can improve low urinary tract symptoms (LUTS), make the international prostate symptom score (IPSS) better, decrease residual urine, and increase the maximum urinary flow rate in BPH; however, it does not increase the volume of the prostate and PSA level (Haider et al., 2009; Abdollah et al., 2011; Corona et al., 2014; Cyrus et al., 2014). Here, KLK3 is linked to benign prostatic hyperplasia.