OLIG2 and neoplasm: This invasion mechanism, reminiscent of OPC-endothelial migration99, has been linked to OLIG2+/Wnt7b+ tumor cells50, which is in line with our results indicating OLIG2-positive, OPC-like glioma cells as predominant tumor cells in our model system, and the observed increases in WNT signaling of this cell compartment in Pdgfbret/ret tumors (Fig. S8C).