IL13 and glioblastoma: Metallofullerenes (i.e., Gd3N@C80) functionalized with hydroxyl and carboxyl moieties (i.e., Gd3N@C80(OH)26(CH2CH2COOH)16) were able to conjugate with the fluorescent label, i.e., 5(6)-carboxytetramethylrhodamine (TAMRA), and peptide, namely interleukin-13 (IL-13), which is a significant receptor on the GBM cells.