Cdc25A (also know as M-phase inducer phosphatase 1 and dual specificity phosphatase Cdc25A) is a 65 kD MPI phosphatase containing a rhodanese domain. This nuclear protein functions as a dosage-dependent inducer in mitotic control required for the progression of cell cycle. Cdc25A activates Cdc2 by dephosphorylation, dephosphorylates CDK2 in complex with cyclin E. Cdc25A is timulated by cyclins B, downregulated by Chk1 and Cds1/Chk2 phosphorylation. This phosphatase has been shown to interact with Cdc2, cyclin B, Cdk2, Chk1, and Chk2. The Poly6207 antibody recognizes phosphorylated human Cdc25A (Ser17) and has been shown to be useful for Western blotting.