Further studies showed that β-elemene (45 mg/kg, i.p.)significantly improved the radiosensitivity (6 MV electron beam from a linear accelerator, 5 Gray) of A549 cells xenograft in vivo by suppressing the HIF-1α-survivin pathway and directly or indirectly downregulating the mRNA and protein expression of radiation-induced peroxiredoxin-1 (Prx-1), a critical molecule in redox regulation of tumor cells [71,72]. Here, BIRC5 is linked to neoplasm.