A high expression of CDK1 (HR 1.55 [1.25–1.92], P = 6.1e-05), CCNA2 (HR 1.53 [1.23–1.9], P = 9.9e-05), TOP2A (HR 1.84 [1.48–2.29], P = 3.1e-08]), CCNB1 (HR 1.91 [1.53–2.37], P = 4.1e-09), KIF11 (HR 1.54 [1.24–1.91], P = 7.5e-05]), and MELK (HR 2.04 [1.64–2.54], P = 9.2e-11) was related to a worse OS in breast cancer patients (Figure 7). This evidence concerns the gene CCNB1 and breast cancer.