TMPRSS2 and posterior cortical atrophy: Fusion of the TMPRSS2 (transmembrane protease, serine 2) and ERG (a member of the E26 transformation-specific family of oncogenes) genes is highly specific for PCa, as well as displaying 93.2% specificity for predicting clinically significant PCa.12,26 This gene fusion has been found in approximately 50% of PCa patients, and fused RNA transcripts can be detected in the urine, providing the added benefit of being a non-invasive test 27.