KLK3 and prostate cancer: Originally, PSA was used to detect prostate cancer recurrence or progression, but later it became widely used for screening, as guidelines were issued accepting it as a screening tool.6,7 This led to increased detection of prostate cancer, mainly low-risk localized disease.8 Eventually, surgery and radiation therapy were increasingly utilized to cure these cancers, consequently leading to increased adverse events and morbidity.9–12