CDK2 and breast cancer: In terms of the patient outcome, CDK2/CDK6 co-expression influences the survival outcome (p < 0.0001) (Figure 2G), and this association was maintained in luminal BC (p < 0.0001) (Supplementary Figure S4B), including endocrine-therapy-treated patients (Supplementary Figure S4C), but not in endocrine-therapy-naïve patients (Supplementary Figure S4D).