CDC25C and cancer: Direct mechanisms include 1) phosphotyrosine phosphatase activation, 2) tyrosine kinase inhibition, 3) cell cycle arrest by downregulation of phosphorylation and activation of the rat sarcoma virus/MAPK pathway, 4) apoptosis of cancer cells by intracellular acidification and endonuclease activation, and 5) inhibition of GH and cytokines by inhibition of cyclic adenosine monophosphate and calcium production.