Plays a role in mitotic cell cycle progression and is involved in kinetochore assembly and mitotic sister chromatid cohesion. Probably through its association with CBX5 plays a role in mitotic chromosome segregation by regulating aurora kinase B/AURKB activation and AURKB and CBX5 dissociation from chromosome arms (PubMed:20562864). Promotes the repair of DNA double-strand breaks through the homologous recombination pathway (PubMed:26721387).