Activation of the cyclin A:Cdc2 complexes at mitosis requires the removal of the inhibitory phosphate groups on Cdc2 (CDK1). This dephosphorylation is achieved by the activity of the CDC25A phosphatase (Timofeev et al. 2009). CCNA:CDK1 was reported to suppress the expression of CDC25A to safeguard timely mitotic entry (Ng et al. 2023). CDC25A, CDC25B, and CDC25C are kept inactive during interphase and are activated at the G2/M transition (reviewed in Wolfe and Gould 2004). The peak activity of CDC25A precedes the one of CDC25B. While CDC25A activates both CCNA:CDK1 and CCNB:CDK1 complexes, CDC25B seems to be involved only in activation of CCNB:CDK1 (Timofeev et al. 2009).