Fibroblasts, an inconspicuous but essential player in colon cancer development and progression

Figure 4 Double-edged actions of cancer associated fibroblasts in tumor immunity. CAFs exhibit double-edged actions in tumor immunity. In most types of cancers, CAFs can dampen tumor immunity by suppressing T cell proliferation, NK cell activity, and DC maturation, and inducing Treg proliferation and MDSC accumulation. In some types of cancers such as pancreatic ductal adenocarcinoma, CAFs can enhance tumor immunity by enhancing effector T cell and NK cell functions and depressing Treg activities. CAFs: Cancer associated fibroblasts; VEGF: Vascular endothelial growth factor; MDSC: Myeloid-derived suppressor cells; NK: Natural killer.