Ansari et al. reported that Ferumoxytol conjugated to azademethylcolchicine via an MMP14-cleavable linker (Ferumoxytol-FITC-VDA) induced significant necrosis in MMP-14 expressing glioblastomas and not normal brain.19 Furthermore, Mohanty et al. demonstrated that Ferumoxytol-FITC-VDA significantly impaired tumor growth and improved survival of experimental mice.20 None of these studies correlated NP-mediated tumor contrast enhancement on MRI with in vivo NP tumor accumulation at the microscopic level. Here, MMP14 is linked to glioblastoma.