TNF and gastric cancer: In addition, as host genetic factors, the TNF-A, IL-1B, and IL-1RN genetic polymorphisms, which influence serum and gastric mucosal TNF-α and IL-1β levels, are inversely associated with the risk of reflux esophagitis development in H.-pylori-positive patients because their specific genotypes (e.g., IL-1B-511 T/T, IL-1RN *2/*2, TNF-A-857 T/T, -863 A/A, and -1031 C/C types) are linked to severe gastric mucosal atrophy, development of peptic ulcers and gastric cancer, and hypochlorhydria [6].