Apart from traditional tests and imaging (including the prostate-specific antigen (PSA) test, digital rectal exam, biopsy, computed tomography (CT), and magnetic resonance imaging (MRI)), an imaging technique called prostate-specific membrane antigen positron emission tomography (PSMA PET) is more specific and sensitive, targeting PSMA expressed by prostate cancer cells on their surface. Here, KLK3 is linked to prostate cancer.