However, when the tumor is targeted, the weakly acidic and high GSH of TME disrupts the PDGFB-FMS, causing its nanostructure to collapse, resulting in the rapid release of Mn2+ ions, which separates from the Fe3O4 magnetic core and activates the dual-mode of the T1 and T2 MRI signals. Here, PDGFB is linked to neoplasm.