PAK1 is one of six members of the PAK family of serine/threonine kinases which are broadly divided into group I (PAK1, PAK2 and PAK3) and group II (PAK4, PAK6 and PAK5/7). PAK1 localizes in distinct sub-cellular domains in the cytoplasm and nucleus which regulates cytoskeleton remodeling, phenotypic signaling and gene expression, and affects a wide variety of cellular processes such as directional motility, invasion, metastasis, growth, cell cycle progression, angiogenesis.