CCNE1 and ovarian serous adenocarcinoma: In high-grade serous ovarian cancer cases, Cyclin E1 is connected with chromosomal instability, the overexpression of which is associated with an increased copy number of USP28, although the effect induced by alteration of USP28 is relatively weaker than CCNE1 (encodes Cyclin E1) amplification [34, 63].