We first evaluated tumor-infiltrating FOXP3+ cells in gastric MALT lymphomas and, to study them in the context of other lymphoid conditions of the stomach, we analyzed samples with chronic gastritis, as precursor lesions preceding gastric MALT lymphomas, and gastric diffuse large B-cell lymphoma, as late event lesions resulting from progression of gastric MALT lymphoma. This evidence concerns the gene FOXP3 and gastric mucosa-associated lymphoid tissue lymphoma.