Consistent with the microarray data, MMP3, PDGFRB, CTSD, BIRC5, CTSC, PTTG1, IGFBP3, and LGMN were found to display, respectively, 6-, 6-, 7-, 8-, 14-, 18-, 19- and 19-fold higher expression in the invasive cancer stroma than in PIN stroma. This evidence concerns the gene PTTG1 and prostate intraepithelial neoplasia.