PDGFB and glioma: Consistent with this, direct assessment of patient tumors by immunohistochemistry of the TMA found that high levels of p-STAT3 significantly correlated with expression of IL-33 (Fig. 8c) and consistent with these observations, high levels of p-STAT3 were detected in IL-33-expressing BT147, BT53 and the PDGFB-driven glioma models in vivo (Fig. 8d–f).