My laboratory is interested in understanding the molecular pathological mechanisms underlying the development and progression of prostate cancer. The androgen receptor (AR), a ligand-dependent transcription factor belonging to the nuclear hormone receptor (NR) superfamily, plays a critical role in the onset and progression of prostate cancer. Recently, we have mapped AR binding regions in the entire human genome in prostate cancer cells by using genome-wide chromatin immunoprecipitation (ChIP) techniques. Through an integrated analysis of AR binding and gene expression data, we have begun to understand how AR regulates target genes involved in prostate cancer growth. Currently, we are extending our view from transcriptional regulation by AR to wider transcriptional regulations in prostate cancer including studying combinatorial transcriptional regulation by AR, its collaborating transcription factors, and its coactivators. We will also apply global ChIP techniques to clinical samples obtained from different stages of prostate cancer. This would allow identification of critical cis-regulatory sequences contributing to prostate cancer progression.