KLK3 and prostate carcinoma: There is level-1 evidence from multiple studies, including the STHLM3-MRI (Prostate Cancer Screening With PSA, the Stockholm3 Test, and MRI) trial on which the present trial is based, that performing magnetic resonance imaging (MRI) in patients with moderately elevated PSA levels can reduce unnecessary biopsies while maintaining the ability to detect clinically significant prostate cancer.2,3,4,5 Current guidelines from the European Association of Urology6 and the National Comprehensive Cancer Network7 recommend obtaining an MRI of the prostate before diagnostic biopsy.