FHIT and esophageal cancer: Among the six MRGs, FHIT is a well-documented tumor suppressor and its expression was also downregulated in other malignant tumors including bladder, breast, esophageal cancer, head and neck squamous cell carcinoma, renal chromophobe cancers, renal clear cell carcinomas, lung squamous cell carcinomas, and thyroid carcinomas (Figure 8A).