PAK1 and colitis: Blebbistatin protects Lgr5+ stem cells against colitis-induced epithelium injury in gastrointestinal tissues through the Myh9-Rac1-PAK1-Akt pathway (Zhao et al., 2015) and induces cell migration through myosin-II-related matrix stretch and recoil (Vicente-Manzanares et al., 2009).