FN1 and central nervous system cancer: Plasma- and serum-derived protein markers—such as immunosuppressive acidic protein, alpha-1 acidic glycoprotein and alpha-1 antitrypsin, the glycoprotein fibronectin, and the endothelial cell-derived thrombomodulin-1—were the first proteins to be found elevated in the blood of patients with glioma [84, 110, 141, 145], followed by protein markers related to angiogenesis in gliomas.