 When cyclin B levels are elevated, cells can enter M phase prematurely and strict control over cell division is lost, which is a favorable condition for cancer development.On the other hand, if cyclin B levels are depleted the cyclin B/CDK1 complex cannot form, cells cannot enter M phase and cell division slows down.Some anti-cancer therapies have been designed to prevent cyclin B/CDK1 complex formation in cancer cells to slow or prevent cell division.