IL-6 is well known to play a role as a tumorigenic factor in GC,75–78 and higher serum IL-6 levels are independent predictors of a poor prognosis in patients with GC.79,80 IL-6 binds to the alpha subunit of its specific receptor and to the gp130 homodimer on the cell membrane,81 and it activates two major signaling pathways: SHP-2/ERK and JAK/STAT.82,83 The SHP2/ERK and JAK/STAT signaling pathways are considered to play opposing roles in gastric epithelial cells, and their balance maintains the homeostasis of the gastrointestinal mucosa. This evidence concerns the gene IL6 and gastric cancer.