To get a thorough picture of this complex heterogeneity, we analysed two complementary single‐cell RNA sequencing datasets: GSE197543 [22], encompassing diverse cell populations from GBM centre and periphery regions (Figure 1A), and GSE162631 [23], comprising CD31+ immune cells that were specifically isolated from the corresponding regions (Figure 1B). The gene discussed is PECAM1; the disease is glioblastoma.