The imbalance of type 1 cytokine/type 2 cytokine expression was found in H. pylori-associated gastric diseases. The ratio of plasma IFN-γ/IL-4 (a), IFN-γ/IL-5 (b), IFN-γ/IL-13 (c) decreased along with the progression of gastric cancer, including chronic atrophic gastritis (CAG) and gastric cancer (GC). Moreover, H. pylori infection exacerbated this trend. IFN-γ (d) mRNA decreased, but IL-4 (e), IL-5 (f), and IL-13 (g) mRNA expression increased in PBMCs derived from the H. pylori-infected individuals along the gastric cancer progression, when compared to those without H. pylori infection. ∗p < 0.05, ∗∗p < 0.01, and ∗∗∗p < 0.001.