Taken together, these results indicate that NKX6.3 can regulate cell proliferation and apoptosis as well as cell motility and invasion processes by preventing accumulation of genetic alterations through downregulation of AICDA, NFκB, CBFβ, and APOBEC3B expression in gastric epithelial cells, thereby contributing to the development and progression of gastric cancer. This evidence concerns the gene APOBEC3B and gastric cancer.