AURKB (aurora kinase B, AIK2 or aurora-B), with 344-amino acid protein(about 39kDa),localizes to microtubules near kinetochores, specifically to the specialized microtubules called K-fibers. AURKB is a mitotic protein kinase, which phosphorylates histone H3 and regulates Chromosomal segregation during mitosis and meiosis.It may regulates several stages of mitosis such as centrosome separation, chromosome segregation and cytokinesis.Component of the chromosomal passenger complex (CPC), a complex that acts as a key regulator of mitosis. The CPC complex has essential functions at the centromere in ensuring correct chromosome alignment and segregation and is required for chromatin-induced microtubule stabilization and spindle assembly. ARK-2 transcripts arepresent at high levels in human thymus and fetal liver.ARK-2 protein levels are maximal during both S and G2/M phases