CXCR2 and cancer: There is considerable evidence that CSC enrichment played a key role in contributing to chemotherapy resistance of DTX.28,60 CXCR2 was reported to induced epithelial-to-mesenchymal transition (EMT) of breast cancer cells and proposed as a novel marker of BCSCs.61–63 In our study, we used SB225002, a selective CXCR2 antagonist with promising therapeutic effect in cancers,46 to blocking CXCR2 in breast cancer cells.