PCA3 is a gene that is highly over-expressed in more than 90% of prostate cancers, and that can be quantified in urine specimens following a digital rectal examination. Studies have shown that because PCA3 is highly specific for prostate cancer, it predicts the results of repeat biopsies more accurately than traditional prostate-specific antigen (PSA) testing. Gen-Probe's PROGENSA(R) PCA3 assay is the first urine-based molecular diagnostic assay for prostate cancer.