Tyrosine protein phosphatase which functions as a dosage- dependent inducer of mitotic progression (PubMed:12676925, PubMed:14559997, PubMed:1836978, PubMed:20360007). Directly dephosphorylates CDK1 and stimulates its kinase activity (PubMed:20360007). Also dephosphorylates CDK2 in complex with cyclin-E, in vitro (PubMed:20360007). {ECO:0000269|PubMed:12676925, ECO:0000269|PubMed:14559997, ECO:0000269|PubMed:1836978, ECO:0000269|PubMed:20360007}. This is the function of CDC25A (cell division cycle 25A, Ensembl gene identifier ENSG00000164045).