IGFBP7 and central nervous system cancer: The high expression and accessible nature of the IGFBP7 target in GBM vessels, combined with virtually non-existent expression in normal vessels, in combination with demonstrated versatility and good in vivo targeting characteristics of anti-IGFBP7 sdAb, indicate that linking of this antibody to the appropriate optical, PET or MRI contrast agents could enable in vivo imaging assessment of the degree of angiogenesis in gliomas.