ERG and prostate cancer: The validation study differs from the meta-analysis studies in the following aspects: a) independent patient cohort (n = 57) selected from the Innsbruck prostate cancer biobank; b) alternative gene expression technology (validation study, Illumina BeadChip arrays; meta-analysis studies, Affymetrix GeneChip microarrays); and c) ERG+ and ERG− group assignment (Figure 3A).