It has been found that epidermal growth factor (EGF), platelet derived proliferation factor (PDGF) and their receptors are overexpressed (Ronellenfitsch et al., 2010[34]) in glioblastoma tumors; c-met and PDGFR are co-expressed in resistance mechanisms against EGFR inhibitors (Stommel et al., 2007[35]). Here, EGF is linked to glioblastoma.