It has been suggested that decreased prostate volume, biopsy density and/or prostate-specific antigen (PSA) performance may have contributed to the detection of more poorly differentiated prostate cancer in PCPT men [34-38], but our findings support that the increased incidence of high-grade prostate tumors seen in PCPT was an adverse effect of finasteride treatment. The gene discussed is KLK3; the disease is prostate neoplasm.