While MCPs were expressed under both NSC and FBS conditions at P1 (Supplemental Figure 11D), at later P6, PDGFB-driven primary cells had reduced MCP expression, while Nf1-silenced cells showed high expression regardless of the number of passages (Supplemental Figure 11E), indicating that Nf1-silenced tumor cells are less reliant on stromal support for MCP induction, which is consistent with the high levels of IL-1β in the tumor cells of this GBM molecular subtype (MES). Here, IL1B is linked to glioblastoma.