ID4 and prostate cancer: Normalized Id4 expression analysis in these samples indicated: 1) High Id4 in benign prostate hyperplasia as compared to prostate cancer suggesting that decreased Id4 is a cancer specific event 2) High normal adjacent (NAP) and post pubertal (PP) Id4 gene expression that may signify the role of Id4 in maintaining normal prostate function and 3) Low Id4 expression in prostate cancer (metastatic prostate cancer < prostate cancer).