Tumor vasculature, following the action of the MMP14-cleavable VDA, showed fragmented and irregular CD31-positive staining together with brown particulate (endothelial cell debris), indicating significant endothelial cell damage and vessel collapse.49 These observations validated the findings made with IVM, confirming the impact of VDA on tumor blood vessels and theranostic properties of Ferumoxytol-FITC-VDA. Here, PECAM1 is linked to neoplasm.