Interleukin (IL)-8 secretory response in AGS cells induced by IL-1β (0.2–20 ng/ml) and Helicobacter pylori (Hp) (multiplicity of infection (MOI)=50 and 100), as measured by enzyme linked immunosorbent assay. M, cell culture medium alone; C, cell culture medium from untreated AGS cells. n=3, **p<0.01, ***p<0.001 versus untreated cells.