TF and glioblastoma: Guo et al. [128] modified the surface of RES-loaded polyethylene glycol‒polylactic acid nanoparticles with transferrin moieties (Tf-NP-RES), which led to increased intracellular uptake, higher cytotoxicity, and apoptosis of rat C6 and human U-87 MG GBM cell lines in vitro compared to free RES and nanoparticles without transferrin.