Shi and colleagues have also observed that glioma tissue areas with extensive Iba1+ TAM infiltration showed increased PTN staining [72], suggesting that both Iba1+ microglia and CD163+ microglia-derived macrophages may play a role in supporting the survival and migration of GSCs; this paracrine signaling is tentatively visualized in Figure 6. This evidence concerns the gene CD163 and central nervous system cancer.