CRPC is a late-stage prostate cancer typically evolved years after androgen deprivation therapy.Very recently,there has been a rapid increase in the number of effective systemic agents for men with metastatic CRPC (mCRPC),1 including abiraterone acetate and Enzalutamide (hormonal therapies),Sipuleucel-T (immunotherapy),Cabazitaxel (chemotherapy),Denosumab and Radium 223 (bone microenvironment targeting agents).However,the genetic heterogeneity of prostate cancer,the high cost of these therapies,and the uncertainty of the best use for these drugs in clinical decision-making,have highlighted the need for novel effective biomarkers to identify the right therapy and timing for the right patient and enable the monitoring of therapeutic response and disease progression.