PAK1 and cancer: PAK1 is overexpressed and hyperactivated in a variety of cancers [13], [21]–[25], and can mediate downstream signaling events that are involved in cytoskeletal reorganization, cell motility, cell cycle, epithelial mesenchymal transition (EMT), invasion and chemoradiotherapy efficiency through multiple layers of mechanisms such as translation, transcription and RNA splicing [13], [26], [27].