A primary aim of this study is to determine the molecular effects of BoNT-A injection on human BPH tissues. While the majority of BoNT-A injections in humans target BPH in the transition zone, innervation is most abundant in the peripheral zone of the prostate where the majority of prostate cancers develop. In fact, recent studies have demonstrated the importance of neurogenesis and axogenesis in the spread of human prostate cancer. In addition, in vitro studies have shown that BoNT-A has antiproliferative effects on human prostate cancer cell lines.