In total, 11 DNA repair genes (UBE2A, RBBP8,RAD50, FAAP20, RPA3, ENDOV, DDB2, UBE2V2,MRE11, RRM2B, andPARP3) were preserved as prognostic genes to estimate risk score, which was applied to establish the prognostic model and stratified breast cancer patients into two groups with high or low risk. This evidence concerns the gene RRM2B and breast cancer.