||CEP55 (Centrosomal protein of 55 kDa， also known as URCC6 (Up-regulated in colon cancer 6， is a 464 amino acid protein that localizes to the centrosome during interphase and may be found throughout the cell during mitosis. Widely expressed with highest expression in testis and lower expression in thymus, bone marrow, placenta, fetal heart, digestive tract and several carcinomas, CEP55 exists as a homodimer that interacts with centrosome components and is involved in mitotic exit and cytokinesis. Human CEP55 undergoes several phosphorylation events throughout the cell cycle, most of which are necessary for proper CEP55 function. Mutations or defects in the gene encoding CEP55 result in a failure to exit mitosis and may be associated with tumor progression. Two isoforms of CEP55 are expressed due to alternative splicing events.