Cdc25 is a protein phosphatase responsible for dephosphorylating and activating cdc2, a crucial step in regulating the entry of all eukaryotic cells into mitosis. Breast cancer patients bearing tumors containing high levels of Cdc25B have been found to have a greater incidence of aggressive, high-grade tumors than those with low Cdc25B levels. CDC25B is nuclear in the M and G1 phases of the cell cycle and moves to the cytoplasm during S and G2. Multiple transcript variants for this gene exist. In addition, Cdc25 proteins from a variety of species have been shown to share a low degree of sequence similarity with other Tyrosine phosphatases.
