Frequent inactivating mutations were also identified in Hippo pathway regulators FAT1, FAT2, FAT3, and FAT4 (27%) or AJUBA (7%) by exome sequencing on a large cohort of northern Chinese cases [14], providing a genetic mechanism for high-level nuclear YAP expression/activation in ESCC. This evidence concerns the gene FAT1 and esophageal squamous cell carcinoma.