Figure 5. A graphical flow chart recapitulating the alterations of tumor microenvironment after Sutent monotherapy. The Sutent treatment has anti-vascular effects, which not only result in formation of chronic hypoxic regions within the tumors, but also improves pericyte coverage and adhesion molecules expression on the vasculature. Increasing levels of CXCL5, G-CSF, IL-1α and IL-6 is correlated to PMN-MDSCs expansion in blood. In addition, increased expression of several cytokines and chemokines contributes to the maintenance of CD68+ TAMs and Ly6G+ PMN-MDSC within the tumor microenvironment and induces their redistribution around chronically hypoxic regions. These effects might compensate for the reduction of MDSCs by Sutent treatment.