CDCA8 is a component of a chromosomal passenger complex (CPC) required for stability of the bipolar mitotic spindle. The chromosomal passenger complex, which includes Survivin, CDCA8, INCENP and Aurora-B, is known to play crucial roles during mitosis and cell division. It was found that CDCA8 interacting with Aurora-B, INCENP and Survivin, increases during G2/M phase and then reduces after exit from M phase. CDCA8 is cell cycle regulated, down-regulated in response to p53/Rb-signaling, and up-regulated in many types of cancerous tissues. In Drosophila cells, inactivation of CDCA8 results in polyploidy, delayed mitosis and abnormal tissue development, indicating its critical role for cell proliferation. Recent studies show that CDCA8 is essential for cell proliferation during early embryonic development, and its early embryonic lethality cannot be rescued by the loss of p53. Its aberrant expression is linked to a poor prognosis for gastric cancer.