Currently,the prognosis of patients with metastatic prostate cancer is most commonly defined by clinical factors including performance status,presence of visceral metastasis,lactate dehydrogenase level,opioid analgesic use,albumin level,presence of anemia,prostate-specific antigen level,and alkaline phosphatase level(i.e.,Halabi model).1 This model is most commonly used in the current prospective clinical trials today.However,it is only an inference of the underlying biology and not a direct measurement of that biology.