RAC1 and cancer: Cdc42 and Rac1 are well established key regulators of cell migration and invasion processes involved in cancer metastasis [7], therefore it is not surprising for PAKs to be implicated in mediating extracellular signals and regulating cell motility and morphology, cytoskeletal remodeling, cell proliferation and apoptosis, thus contributing to cancer formation, development and metastasis [8].