Firstly, we evaluated the relationship between response to TBR and the expression of STHMN1 and OPN by analyzing pathology specimens obtained from the patients at the time of diagnosis. Resistance to taxanes may be intrinsic or acquired due to long term exposure to this chemotherapeutic agent. We may have overlooked acquired resistance in the specimens in this study. There may be alterations in these specimens during the progression of metastatic process or the long term use of cytotoxic regimens. Specimens obtained by a second biopsy during the progressive period could have provided further findings. Taken together, to the best of our knowledge, heterogeneity of primary tumor specimens of cases diagnosed with mCRPC has not been observed to date. This issue may be clarified further in prospective studies.