Multifunctional protein that may affect its functions by regulating the activity of small GTPases, such as RAC1 and RALA.Required for normal progress through the cell cycle, both during interphase and during mitosis.Required for the presence of normal levels of MAD2L1, AURKB and BIRC5 on inner centromeres during mitosis, and for normal attachment of kinetochores to mitotic spindles.