In particular, reports have suggested that the presence of the TMPRSS2:ERG gene fusion in high-grade prostatic intraepithelial neoplasia (HG-PIN) may be a harbinger of T2E fusion-positive prostate cancer49; hence, HG-PIN may represent a suitable model system for this mode of discovery. This evidence concerns the gene TMPRSS2 and prostate intraepithelial neoplasia.