Remodelling of calcium signalling by altered expression of these key ion channels is likely to be the driving force behind cell migration and invasion in GBM and it would play a large contributing factor to drug resistance [246,269], particularly in EGFR-targeted therapies, as we have described that these calcium-dependent ion channels and regulators may themselves activate the signalling cascades associated with RTK activity. This evidence concerns the gene EGFR and glioblastoma.