TMPRSS2 and prostate cancer: Of these, overexpression of the ETS-related gene (ERG) [6, 7], resulting from the fusion of ERG coding sequences to the androgen-responsive TMPRSS2 gene [8], represents the most common subtype among ETS fusions, with a prevalence of approximately 50% in clinically localized prostate cancers [1-4, 9-12].