AXL and cancer: In the present study, we have identified for the first time a protein-protein interaction between EGFR and Axl, in which Axl acts as a gateway for EGFR to access pro-invasive signalling pathways in GBM cells, which are known for their highly invasive and proliferative phenotype,20 and which overexpress both RTKs.14, 21 This unconventional hetero-interaction among RTKs of different classes diversifies the signalling pathways accessible to both RTKs, and indicates that EGFR-Axl signalling could act as a master regulator of chemoresistance in several cancers.