KLK3 and medical procedure: The mean age of the BCG prostatitis group was 66.2 ± 11.3 years, and the mean age of the negative group was 67.2 ± 10.8 years; the pre-BCG instillation PSA levels of each group were 1.87 ± 1.49 ng/mL and 1.55 ± 1.92 ng/mL, and the estimated prostate volumes were 33.8 ± 10.7 mL and 30.8 ± 11.7 mL, respectively.