Gene fusions prevalent in prostate cancer (CaP) lead to the elevated expression of the ERG protooncogene. ERG activation present in 50-70% of prostate tumors underscores one of the most common oncogenic alterations in CaP. Despite numerous reports of gene fusions and mRNA expression, ERG oncoprotein status in CaP still remains to be defined. Furthermore, development of ERG protein-based assays may provide a new dimension to evaluation of gene fusions involving ...