In order to select cytokines distinguishing GC, cytokines found significantly different between GC and EC in univariate analysis (IL-1β, IL-1ra, IL-4, IL-9, IL-12(p70), IL-13, IFNγ, GM-CSF, MCP-1, PDGF-BB, and FGF2) were entered as explanatory variables into logistic regression analysis. The gene discussed is IL9; the disease is gastric cancer.