Prostate cancer is a major health problem for men. The incidence of prostatic cancer has risen so dramatically during the past decade that it has become the most commonly diagnosed non-cutaneous malignancy in males of the western world, and the second mos t common cause of cancer death among men in Europe and the United States, second only to lung cancer. However, the basic biology of prostate cancer remains largely elusive at this time. This information is crucial to develop new diagnostic and therapeutic modalities to fight prostate cancer. The goal of our research program is to provide this basic information that can immediately be applied towards clinical endpoints. Specifically, our studies focus on the important role of androgens in the development o f prostate cancer which was first recognized over 60 years ago for which the molecular mechanisms are still largely unknown. By identifying androgen target genes and providing the molecular details of how androgens exert their effects on prostate cancer c ells, the results of the research program is expected to contribute not only to a better understanding of androgen action, but also provide molecular tools that can be exploited in the diagnosis and therapy of prostate cancer.