Separase is a cysteine protease that plays a crucial role in cleaving cohesin during mitosis, allowing sister chromatid separation. Its activity is regulated by the inhibition of the Securin protein. Separase is primarily localized in the nucleus and is involved in the precise regulation of the cell cycle. Its expression is periodic and closely associated with different stages of the cell cycle. Mutations or abnormal expression of the Separase gene can lead to unequal chromosome distribution, leading to chromosomal instability and cancer.