Figure 10: Constitutive EGFR signalling in GBM.

(a,b) EGFR levels in 27 GBM tumours by real-time quantitative PCR. An arbitrary cutoff of 1 or above was considered to be EGFR overexpression and corresponded well to expression levels of EGFR on western blot (Supplementary Fig. 17D). (c,d) TGF-α, IFIT1 and IFI27 levels in GBMs expressing a low level of TGF-α (less than 1) measured by real-time quantitative PCR. (e,f) TGF-α, IFIT1 and IFI27 levels in GBM tumours expressing a high level of TGF-α measured by real-time quantitative PCR.