Inhibition of HER RTKs by HER pan-inhibitor CI-1033 notably enhances the radiosensitivity of human colon carcinoma cells both in vitro and in vivo (22), while HER1 inhibition by gefitinib and HER2 inhibition by herceptin, respectively, radiosensitizes EGFR amplified glioma cells and breast cancer cells (23,24). This evidence concerns the gene ERBB2 and breast carcinoma.