"NOX4 knockout cell lines showed reduced cell proliferation with an increase of sub-G1 cell population and the decrease of S/G2/M population and resulted in a dramatic decrease in invadopodium formation and the invasive activity. NOX4 deficiency caused a decrease in focal adhesions and cell migration in HeLa cells. The results suggest that NOX4 is required for both efficient proliferation and invasion of HeLa cells."xsd:string