CXCR4 and nonpapillary renal cell carcinoma: The results showed that silencing of CXCR4 enhanced the promoting effects of DDP on cell apoptosis and death in ccRCC cells, while CXCR4 overexpression had opposite effects and rescued cell viability in ccRCC cells, indicating that CXCR4 increased DDP-resistance, which were partially supported by the previous studies [36,37].