However, if the improvement of urination symptoms is insignificant or if the prostate volume is 30 cc or more, PSA is 1.5 ng/mL or more, or if the digital rectal examination shows prostatic hyperplasia, the effect can be expected through concomitant administration of 5-alpha reductase inhibitors (5ARIs) [38]. The gene discussed is KLK3; the disease is benign prostatic hyperplasia.