EGF and glioblastoma: Recent mass spectrometry studies found increased protein phosphorylation, including the histone methyltransferase enhancer of zeste homolog 2 and the cell motility protein hyaluronan-mediated motility receptor in GSCs compared with neural stem cells from the adult human brain (48); TGF-β receptor type 2 in GSCs grown with EGF compared with GSCs grown in the presence of serum (49); and activation of S6K pathways in GBM cells compared with non-GSCs (50).