performed a protein analysis in surgical glioma specimens to identify differential patterns of coordinated switch on between glioma-relevant signal transduction pathways, which revealed three patterns of protein expression and activation: Epidermal Growth Factor Receptor (EGFR) expression related to receptor mutation and amplification; stimulation of the platelet-derived growth factor (PDGF) pathway that is mediated by ligands; or loss of Neurofibromatosis type I NF1 gene expression (66). The gene discussed is NF1; the disease is central nervous system cancer.