To confirm the presence of targeted SPIO nanoparticles on EGFRhigh GBM cells, Prussian blue staining was performed to detect the presence of iron oxide on U-87MG and U-251 GBM cells incubated with EGFR-SPIO or lipid SPIO nanoparticles for 24 h. The gene discussed is EGFR; the disease is glioblastoma.