12 upregulated hub genes (TOP2A, MAD2L1, FEN1, EPRS, EXO1, MCM4, PTTG1, RRM2, PSMD14, CDKN3, H2AFZ, CCNE2) and 4 downregulated hub genes (EGFR, FGF2, BCL2, PIK3R1) might serve as diagnosis and poor prognosis biomarkers in breast cancer in the future by more research validation. This evidence concerns the gene RRM2 and breast cancer.