EGFR and glioblastoma: Moreover, due to the complex and heterogeneous nature of human malignancies, including GBM, and the crosstalk between different members of the HER family and with other growth factor signalling pathways in tumour progression, the targeting of the EGFR alone may not be sufficient to produce a therapeutic effect in patients with GBM [1,6,7,8,9,10,11,12].