CCNE1 and ovarian serous adenocarcinoma: CCNE1‐amplification or gain occurs in 20% of all high‐grade OvCa tumors and is associated with primary treatment resistance and reduced overall survival in the entity.5, 6 A recent study, however, shows that 19q12 amplified and nonamplified subsets of high‐grade serous ovarian cancer with the overexpression of cyclin E1 differ in their molecular drivers and clinical outcomes, indicating that Cyclin E1‐driven OvCa should be subgrouped by CCNE1 amplification or overexpression.7