STAT3 and astrocytoma (excluding glioblastoma): Overexpression of EGFR in nestin+ neural progenitors drive astrocytoma-like tumors; PDGF/PDGFR manipulate oligodendroglioma-like tumors,54,177 activating primarily the Janus kinase/signal transducer and activator of transcription 3 (JAK/STAT3), phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR), Ras/MAPK, and transforming growth factor β (TGFβ) pathways (Fig. 4).