TLR2 and gastric adenocarcinoma: Remarkably, epithelial cell TLR2, independent of its expression in hematopoietic tumor-infiltrating cells, was shown to directly promote gastric adenocarcinoma growth in mice [19], while expression and signaling of TLR2 in epithelial cells of the small intestine was dependent on microbial colonization of the gut in mice [18].