IL1B and glioblastoma: To determine whether IL-1β is essential for GBM growth, we generated PDGFB-driven primary tumors in WT (WT;Ntv-a) and Il1b-KO (Il1b–/–;Ntv-a) mice by coinjecting RCAS-PDGFB and RCAS-shP53-Rfp (Figure 3A) (15).