Figure 7.

Cross-section through a theoretical GBM to indicate the position and identity of the sub-types of MΦ as a function of hypoxia development. At the onset of tumor development, only microglia was present. When hypoxia begin to take place, MΦ were attracted to the tumor site and present M0 and M1 phenotypes at the shell of the tumor. Then, M0 and M1 MΦ migrated toward hypoxic zones where they increased the M2 markers. Once arrived to hypoxic zones, MΦ were M2 cells and hypoxia fine-tunes this phenotype.