ABCG2 and breast cancer: The resistance to cisplatin has been reported to be related to the upregulated expression of ABCG2 in various cancers, such as breast cancer,38 esophageal carcinoma cells39 and lung cancer cells.40 In the present study, we found that with proper concentration cisplatin induced the death of CaSki cells, and SOX4-modified CaSki cells exerted different death rates when treated by cisplatin.