We observed that while the knockdown of XRCC4 alone did not significantly decrease the cell viability, the combination of XRCC4 knockdown and cisplatin treatment significantly attenuated the cell viability, suggesting the role of XRCC4 in sensitizing the cytotoxic effect of cisplatin in the ovarian cancer cells (Figure 2b). This evidence concerns the gene XRCC4 and ovarian cancer.