For instance, one of the most prevalent oncogenes expressed in prostate cancer is that of ETS-related gene 1 (ERG) (22) and members of the ETS family of transcription factors (ERB, ETV1, ETV4) are placed under the control of an androgen-regulated promoter that occurs in the transmembrane protease, serine 2 (TMPRSS2), resulting in a gene fusion TMPRSS2-ERG that occurs in up to 50% of localized or metastatic prostate cancer. Here, ERG is linked to metastatic prostate carcinoma.