IL13RA2 and central nervous system cancer: IL13Rα2+ U251MG cells retained a very high (above 92% positive cells) expression of IL13Rα2 on their cell surface after lentiviral transduction, whereas IL13Rα2.KDU251MG glioma cells were mostly IL13Rα2 negative (about 12% of IL13Rα2-positive cells) (Fig. 5a).