The brain has a distinct immune composition within the tumor microenvironment, largely consisting of Tumor Associated Macrophages (TAMs)—microglia (MG) and BDM, with poor infiltration of lymphocytes.23 Investigation of the immune compartment across the IDH-wt GBM samples revealed variation in CD45+ infiltration, and an enrichment of CD68+ TAMs in GBM-1 and GBM-2 (Figure 4A). The gene discussed is IDH1; the disease is glioblastoma.