CCNE1 and breast cancer: In order to examine the effect of FBW7 on EglN2 protein levels in breast cancer cell lines, we downregulated FBW7 expression levels by two independent hairpins in breast cell line MDA-MB-453 with wild type FBW7 expression and found FBW7 depletion led to increased EglN2 and Cyclin E1 levels (Figure 3A).