Cell Division (IMAGE) Universität Bayreuth Caption Left: In a healthy cell separase becomes active only after NEK2A has already been degraded - MCL1 and BCL-XL are not cleaved. Right: In cells with a defective spindle assembly checkpoint cell division is sped up. The enzymatic activities of NEK2A and separase timely overlap (purple area) - apoptosis is triggered. Credit Image: Olaf Stemmann. Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.