TP53BP1 and cancer: [12]. Our previous studies also have demonstrated that 53BP1 showed a gradual decreased protein levels during the progression of breast cancer and it had lower expression in cancer lesions than in the matched non-tumor lesions. In addition 53BP1 could inhibit cell proliferation and invasiveness of breast cancer through nuclear factor-kappaB pathway [13]. All the above data raise the question whether 53BP1 has the effect on 5-Fu treatment of breast cancer.