AJUBA and esophageal squamous cell carcinoma: Inactivation of Hippo signaling due to mutations of its upstream inhibitors such as FATs, AJUBA and Dachsous cadherin-related 1 (DCHS1) or its core components such as MST2 and LATS1 (19), and increased expression of its downstream effector YAP has been reported in ESCC (7, 20).