ERG and prostate cancer: The ExoDx Prostate (IntelliScore) test, measuring the exosomal gene expression of TMPRSS2-ERG and PCA3 in non-DRE urine samples, has recently demonstrated the independent diagnostic value to discriminate high-grade from low-grade and benign prostate disease in Caucasians, improve clinical identification of high-grade prostate cancer, and reduce the number of unnecessary biopsies [24, 26, 27].