The lymphocyte count reflects the degree of responsiveness of the immune system of the host.[24,25] Tumor-infiltrating lymphocytes (TILs) are important immune cells found within tumors and are responsible for antitumor immune responses.[26] Amedei et al[27] found that TILs cells from Helicobacter pylori infected patients with gastric cancer showed poor cytolytic activity while expressing helper activity for monocyte MMP-2, MMP-9, and VEGF production, which play an important role in angiogenesis, tumor invasion, and metastasis. This evidence concerns the gene MMP9 and gastric cancer.