Given the dismal prognosis of patients with rectal cancer and the variation in response to radiotherapy, a reliable biomarker of intrinsic tumor radiosensitivity would improve assessment of prognosis and aid in making proper treatment decisions. It would help to avoid adverse side effects of neoadjuvant radiotherapy in patients who are unlikely to benefit, and at the same time identify those who may subsequently benefit from intensification of therapy. Although several biomarkers have been studied as predictors of radiotherapy response , the most extensively studied are MRE11 and the radiosensitivity index (RSI), a multigene expression model of tumor radiosensitivity, which was developed to predict treatment outcomes independent of disease site . However, to date, these biomarkers have not been validated in randomized trials, and their clinical value remains unclear. For instance, Sheridan and colleagues  found no correlation between MRE11 expression and survival or radiosensitivity in patients with CRC, albeit with the limitations of a small sample size and short follow-up period. In our study, MRE11 expression alone was not significantly associated with any clinicopathologic characteristics, while in terms of ATM only low expression in TP was associated with older age and higher histologic grade, whereas ATM expression in TC was not associated with any clinicopathologic characteristics.