USP39 and neoplasm: The abnormal expression of FoxM1 enhanced the expression of genes associated with centrosome amplification and aggregation, which promoted tumor progression by inducing an imbalance in cell cycle regulation (77), whereas USP39 could not only indirectly affect cell cycle progression by deubiquitylating FoxM1 (39), but also affect tumor cell apoptosis by regulating the balance between the expression levels of the pro-apoptotic factor Bax and the anti-apoptotic factor Caspase-3 (40).