CDK2 and breast cancer: A high CDK2 mRNA level was highly associated with ER- BC (p < 0.0001), basal-like BC (p < 0.0001), triple-negative phenotype (p < 0.0001), p53 mutant (p < 0.0001), high-risk NPI phenotypes (p < 0.0001) (Figure 3A–F), and poor survival (Figure 3G) in the ER+ cohort.