RAD51 and neoplasm: After the administration of both VPA and IR, tumor growth was significantly inhibited comparing to IR alone (P < 0.01, Figure 5A), the DSBs detected by γH2AX was enhanced (Figure 5B), the protein level of Rad51 was inhibited (Figure 5B), but RFWD3 protein level was increased (Figure 5B) as compared with IR treatment alone.