FOXP3 and adenoma: To explore this possibility, we evaluated the degree of infiltration of different immune cells (T cells, Tregs, B cells, and macrophages) in situ by immunohistochemically staining tissue sections of mouse ileum for CD3, FoxP3, B220, and F4/80 respectively and quantifying the number of stained cells in both the adenomas and non-tumor epithelium.