SPARC and central nervous system cancer: Of note, an advantage of the T12 peptide is that it binds a site on TfRs distinct from the one to which transferrin binds, thus avoiding potential competition of endogenous transferrin for receptor binding.18 Therefore, by targeting these nutrient transporters (i.e., TfR and SPARC), the functional albumin NPs could achieve biomimetic codelivery to the glioma.