The top upregulated immune genes in GBM necrotic cores were associated with macrophages and included the CD163 marker; chemotactic factors (such as CCL18 and SAA1); and the phagocytosis stimulatory factors (such as IL-8 and MARCO) (Supplemental Figure 1; supplemental material available online with this article; https://doi.org/10.1172/jci.insight.157612DS1). Here, MARCO is linked to glioblastoma.