Figure 3.

TAM ontogeny and tumor geography in GBM. Tumor-associated macrophages (TAMs) in GBM originates from microglia (MG-TAMs) or from bone marrow-derived monocytes differentiating into macrophages upon recruitment (BM-TAMs). These can be distinguished based on the differential expression of the integrin CD49D on BM-TAMs and of the purinergic receptor P2RY12 on MG-TAMs. BM-TAMs that infiltrate into the tumor core are smaller and less branched than MG-TAMs that are found in the peri-tumoral area.