The purpose of this study is to develop a strategy to identify molecular markers of response of advanced prostate cancer to specific therapies using clinically relevant prostate cancer patient-derived xenografts PDXs. The MD Anderson and Michigan teams will interact closely to analyze results and generate a responder ID profile hypothesis. The validity of the responder ID profiles will be assessed in clinical trials. When we were in the process of performing our studies at the MD Anderson site, we were informed that there was a miscommunication between MD Anderson and USAMRMC Animal Care and Use Review Office ACURO and that the animal protocols had not been reviewed by ACURO. Thus we were asked to stop all studies and to return all funds utilized for the project as this could not be executed until the animal protocol is approved by ACURO. In May 2016, we had our animal protocol approved and we started our studies. Since then we have made progress in identifying mechanisms of FGFR signaling response which will help select patients for FGFR blockade.