PAKs (p21-Activated Protein Kinases) are a growing family of serine/threonine protein kinases, which are activated in response to extracellular signals and regulate cell shape and motility. PAKs regulate diverse cellular functions, including gene expression, cytoskeletal actin assembly, MAPK (Mitogen-Activated Protein Kinase) pathways, neurite outgrowth, cell cycle control, and cell apoptosis (Ref.1). The mammalian PAK family consists of six members, which can be divided into two subfamilies according to sequence homology. The first subfamily consists of PAK1 (Alpha-PAK), PAK2 (Gamma-PAK, PAK I) and PAK3 (Beta-PAK). PAK1 and PAK3 are tissue-specific with the highest levels in brain, while PAK2 is ubiquitous. The second subfamily consists of the more recently identified PAK4, PAK5, and PAK6. Alpha-PAK is activated by growth factors such as PDGF (Platelet-Derived Growth Factor) and EGF (Epidermal Growth Factor) and by insulin. Alpha-PAK participates [...]