In MAPK-dependent ovarian cancer cells, ETV5 is both induced by E2F and required for the expression of cell cycle genes, such as CCND2 and PLK2. Thus, genetic events, such as CCND2 copy number gain, cooperate with increased ETV5 activity to drive expression of cyclin D2 when cyclin E-CDK2 activity is chronically inhibited. This evidence concerns the gene PLK2 and ovarian cancer.