 ObjectiveHypothesis: The objective of this proposal is to determine whether SU011248 is an effective treatment in two cohorts of men with advanced prostate cancer: men with androgen-independent prostate cancer AIPC who have not been treated with chemotherapy Group A, and men with taxane-refractory, metastatic disease Group B. We hypothesize that specific serum biomarkers and tumor mutations may predict response and may allow optimal subject selection in the future. 