CCN1 and esophageal squamous cell carcinoma: In our discovery cohort, we observed that the core members (FAT1 and LATS2) of Hippo pathway were significantly underexpressed in the FAT/FRY ESCC subtype, whereas the transcriptional targets of YAP1 (CTGF and CYR61) were significantly increased, verifying the inactivation of Hippo pathway in this subgroup (Figure 6B).