Approximately 1000 radical prostatectomies are performed per year at our institution and we currently have over 14,000 such patients in our database, 6.5% of which are from African Americans. We have collected fresh frozen prostate tumor tissues from more than 1900 patients, represented by more than 7000 frozen tissue blocks. We have created tissue microarrays containing prostate cancer from 926 patients, most with long term follow-up. Core B has the following Specific Aims: 1)To maintain and enhance a repository of prostate tissues containing a wide range of neoplastic and non-neoplastic samples from both fresh frozen and paraffin blocks, prostatic fluids, DNA, RNA, and protein, and, to distribute these samples to SPORE and other investigators; 2) to provide high quality histopathologic diagnoses of tissue specimens and tissue microarrays; 3) To continue to design, produce and distribute tissue microarrays using human prostate tissues, cell lines, and xenografts; 4) To continue to improve and add tools to our open source tissue microarray database and software (TMAJ) (http://tmaj.pathology.jhmi.edu) including the development of new open source image analysis tools