ENG and renal cell carcinoma: Moreover, antibodies against other CSC markers (e.g., CXCR4 antibody, CD105 (endoglin) antibody) have been used in RCC clinical trials (NCT01391130: CXCR4 inhibitor plus sunitinib, NCT01727089: endoglin monoclonal antibody plus bevacizumab, and NCT01806064: endoglin monoclonal antibody plus axitinib).