Many biological factors affect radiosensitivity, including hypoxia, the ability to undergo accelerated repopulation, enrichment in cancer stem cell (CSC) numbers, and immune responses, etc. In two retrospective cohorts of patients with bladder cancer, high levels of MRE11 expression on immunohistochemistry (IHC) were associated with improved cancer-specific survival in patients who received radiotherapy but not in those who underwent surgery [45, 46]. This evidence concerns the gene MRE11 and urinary bladder carcinoma.