The diversity of myeloid-derived cells in glioblastomas is determined, on the one hand, by hypoxic, necrotic, nutrient-deprived, pro-inflammatory complex tissue milieu.41,44–47 On the other hand, the pro-inflammatory microenvironment has a significant influence on systemic immune response and brain myeloid-derived cell composition.16 Local and systemic TREM1-dependent myeloid-derived responses were reported in the form of TREM1+-positive monocytes, Mφ, and neutrophils to brain-related injuries. Here, TREM1 is linked to glioblastoma.