Fig. 3.

TAM-regulate immune network in colorectal cancer. The role of TAM in colorectal cancer is controversial as both anti-tumor and pro-tumor effects have been reported. TAM accumulation at the tumor margin has been most frequently associated with longer patient survival. Although not formally demonstrated, TAM at invasive margin are likely to be less susceptible to the suppressive tumor microenvironment and may produce cytotoxic molecules (ROS, NO and TNF-α). TAM secrete key factors that affect lymphocyte differentiation into Th17 cells (IL-23, IL-6, IL-1β, TGF-β) or Treg (TGF-β, IL-10). While Treg inhibit anti-tumor adaptive immune responses, they may also have beneficial effects by decreasing the production of inflammatory cytokines. The role of Th17 cells in CRC and more in general in human tumors is still an open issue