Immunohistochemistry results for MMP14-staining proved a strong upregulation of MMP14 in the tumor microenvironment,50 and causally validated the targeted action of the theranostic NPs, Ferumoxytol-FITC-VDA, towards GBM, with its MMP14-cleavable VDA. The gene discussed is MMP14; the disease is glioblastoma.