Moreover, some stress signals, such as the activation of growth factors such as platelet-derived growth factor receptor (PDGF-R), epidermal growth factor receptor (EGFR), or the activation of various protein kinase C (PKC) isoforms—key regulators of proliferation and invasion in GBM—can induce the expression of AChE [42], specifically the AChE-R splicing variant. Here, EGFR is linked to glioblastoma.