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. Does not appear to exhibit anti-apoptotic activity. Plays a role in increasing blood vessel size during development (By similarity). Component of the CPC at least composed of survivin/birc5, incenp, cdca8/borealin and/or cdca9/dasra-A, and aurkb/aurora-B. Interacts directly with incenp (via N-terminus). Interacts with rxra; the interaction is stronger in the absence of 9-cis retinoic acids (By similarity). Localizes on chromosome arms and inner centromeres from prophase through metaphase and then transferring to the spindle midzone and midbody from anaphase through cytokinesis. The BIR2 domain is required for vascular development. Ubiquitination is required for centrosome-targeting. Belongs to the IAP family. Truncated N-terminus. Truncated N-terminus. Truncated N-terminus.