Furthermore, focusing on the most promising statistically significant candidates, CDK1, PCNA, EZH2, and BUB1, a gene signature enriched in PT was identified that did not show a significant association with poor OS (p = 0.654) but showed a strongly significant reduced RFS (p = 2.837e-4) in events in untreated luminal breast cancer patients (Fig. 4C and D, respectively). This evidence concerns the gene BUB1 and breast cancer.