The p21-activated kinases (PAKs 1-6; EC 2.7.11.1) are serine/threonine protein kinases whose activity is stimulated by the binding of active Rac and Cdc42 GTPases, both members of the Rho GTPase family of proteins, which are well established key regulators of cell migration and invasion processes involved in cancer metastasis, and control the formation of lamellipodia  and filopodia respectively. The GTPase-activated PAKs function as effectors through their kinase activity, and mediate downstream signalling events that bring about the physiological effects of GTPase signalling[1]. PAK1 acts as an key mediator to control cell proliferation, survival, death and motility. The PAK family members are categorized into two groups (PAK1-3, group I; PAK4-6, group II) based on their structural and biochemical discrepancies. In general, group I PAKs are comprised of two Src homology 3 (SH-3)-binding motifs and a distinctive p21/GTPase binding domain (PBD) overlapped with an auto-inhibitory domain (AID) at the N-terminal region and a conserved non-classical SH3-binding site for the binding of guanine-nucleotide-exchange factor PAK-interacting exchange factor (PIX). The kinase domain can be found at the C-terminal. In contrast, group II PAKs only have a PBD and a kinase domain[2].