The results revealed that protein expression levels of KIFC2, USP9X, and CDK4 were elevated in HR+/HER2– BC tissues relative to matched normal controls (Figure 7, A and B) and that there was a positive correlation in protein levels between KIFC2 and CDK4 (Figure 7C) as well as USP9X and CDK4 in these samples (Figure 7D). This evidence concerns the gene USP9X and breast cancer.