Aurora B is the central enzymatic unit of the chromosomal passenger complex (CPC). In the CPC, Aurora B is associated with the passenger proteins inner centromeric protein (INCENP), survivin, and borealin. Aurora B is a serine-threonine protein kinase essential for chromosome segregation and cytokinesis. Specific roles for Aurora B have been demonstrated in cohesin dissociation from centromeres as well as condensin I binding to chromatin.F112. Substrates of Aurora B kinase activity include desmin, septin 1, INCENP, RAC GTPase activating protein 1, and centromeric protein A.