PTEN and glioblastoma: Both fibroblast growth factor receptors (FGFRs) and SRC family kinases (SFKs) phosphorylate PTEN, and p-PTEN fails to antagonize the PI3K signaling (Fenton et al., 2012), suggesting that loss of control of PI3K signaling is associated with resistance to EGFR inhibitors in GBM.