In line with this proposition, and in keeping with their mesenchymal phenotype, upon intracranial transplantation, we found MET+ cells to generate highly aggressive, 100% penetrant gliomas, that developed significantly faster than transplanted MET− cells (Fig. 7G), irrespective of injection into Pdgfbret/+ or Pdgfbret/ret animals (Fig. S14D). Here, RET is linked to glioma.