EGFR and neurofibroma: Epidermal growth factor receptor (EGFR) is an RTK that is abundantly expressed in neurofibroma and MPNST cell lines, despite not normally being expressed in Schwann cells.26 Indeed, expressing EGFR in Schwann cells in transgenic mice leads to the formation of neurofibroma-like lesions (although at a very low penetrance), whereas an inactivating EGFR mutation decreases its tumorigenic potential in a mouse model of MPNST.27 However, in humans, the EGFR inhibitor erlotinib largely failed to inhibit tumour growth in a Phase 2 trial of patients with advanced stage MPNST28 (NCT00068367).