NFKB1 and gastric cancer: Considering there is a relationship between gastric cancer and the promoter region of NFKB1[9,10] and many reports also showed that the genetic variations in introns might involve alternative gene regulation, transcript processing, or chromosomal rearrangements [16,17,23,24], the association between the rs4648068 polymorphism in NFKB1 and gastric cancer has been studied.