Polo-like kinase 1 (Plk1), belonging to the enzyme family of polo-like kinases (24–26), is a multifunctional regulator of cell-cycle progression (27–29), which has been widely shown to be overexpressed in a multitude of cancer entities including OC (30, 31) and to correlate with poor patient prognosis (32–35). This evidence concerns the gene PLK1 and cancer.