Both TJs and AJs are connected to the actomyosin cytoskeleton, and tightly regulated actomyosin dynamics are critical not only for junction formation, but also for structure and function of TJs and AJs during epithelial tissue homeostasis, and morphogenesis (Lecuit and Yap, 2015; Rodgers and Fanning, 2011; Takeichi, 2014).  Rho GTPases are critical for proper dynamic organization and contractility of junctional actomyosin.  When misregulated, abnormal junctional F-actin polymerization or Myosin II contraction can drive pathological conditions (Ivanov et al., 2010; Marchiando et al., 2010).