IGFBP7 and glioblastoma: The in vivo and ex vivo biodistribution analyses of the systemically injected anti-IGFBP7 sdAb ‘tagged’ with the near-infrared dye Cy5.5 alone or in combination with the 100-fold excess of unlabelled anti-IGFBP7-sdAb or NC sdAb-Cy5.5 were performed in mice bearing a 10-day-old U87MG.EGFRvIII orthotopic GBM tumour using prospective in vivo optical imaging (Figure 3A).