11. The gene product is also associated with centrosome maturation. 12. Centrosomes are the major microtubule organizing center ( MTOC ) in mammalian cells.13. The centrosome cycle consists of four phases that are synchronized to cell cycle. 14. Centrosome duplication is heavily regulated by cell cycle controls.15. The role of centrosomes in tumor progression is unclear. 16. Then NPM is released from binding to an unduplicated centrosome , thereby triggering duplication. 17. Plant cells lack centrosomes as microtubule organizing centers. 18. Aneuploidy and tumorigenesis can also result from centrosome abnormality, particularly centrosome amplification defects. 19. Aneuploidy and tumorigenesis can also result from centrosome abnormality, particularly centrosome amplification defects. 20. Centrosome duplication and maturation regulated by Plk1 occurs from late S phase to prophase.