KLK3 and prostate cancer: The PSMA-targeting radiopharmaceutical 18F-flotufolastat (18F-rhPSMA-7.3) has recently been approved by the U.S. Food and Drug Administration for diagnostic PET imaging of patients with unfavorable intermediate- and high-risk prostate cancer who are candidates for initial definitive therapy and for patients with suspected biochemical recurrence (BCR) based on elevated serum prostate-specific antigen (PSA) levels (5).