 Gene fusions involving ETS family transcription factors (mainly TMPRSS2-ERG and TMPRSS2-ETV1 fusions) have been found in ~50% of human prostate cancer cases.     ///    "We recently generated knockin mouse models for TMPRSS2-ERG and TMPRSS2-ETV1 fusions, utilizing the endogenous Tmprss2 promoter. "    ///    "Although expression of TMPRSS2-ERG or TMPRSS2-ETV1 fusion alone is insufficient to initiate prostate tumorigenesis, they appear to sensitize prostate epithelial cells for cooperation with additional oncogenic mutations to drive frank prostate adenocarcinoma. "