Figure 3.

Tumor microenvironment and metabolism. Cancer cells compete with stromal cells for nutrients supplied by the blood, especially glucose, oxygen and lipids, and excrete compounds such as PD-L1 lactate and protons that are immunosuppressive, and which induce changes in macrophage polarization and thence TILs. Cancer cells may also engulf ECM and debris by macropinocyosis to fuel growth and survival (see text). CAF cancer associated fibroblast; TAM tumor associated macrophage; TIL tumor infiltrating lymphocyte; CA cancer cell. ECM + IF extracellular matrix + interstitial fluid.