EGFR IHC in gliomas. IHC stains for EGFR were semiquantitatively scored on a scale, as follows: 0, negative (A); 1, weak (B); 2, moderate (C); and 3, strong (D). E: EGFR staining is generally weaker in grade II gliomas and equally strong among grade III to IV gliomas. *P < 0.001 versus grade III astrocytoma (G3 astro) and GBM; **P < 0.001 versus GBM. Original magnification: ×200 (A–E).