Component of the chromosomal passenger complex (CPC); a complex that acts as a key regulator of embryonic mitosis. The CPC complex has essential functions at the centromere for ensuring sister chromatid cohesion; recruitment of the CPC to kinetochores; and chromosome alignment and segregation. There is no function in meiotic histone phosphorylation or spindle formation. {ECO:0000269|PubMed:16224046}.