IL13RA2 and glioblastoma: Experiments with GBM cell lines engineered to express either low or high levels of IL13Ra2 (Fig. 3H), along with additional solid tumor lines exhibiting a range of endogenous (SI Appendix, Fig. 7 B and C) IL13Rα2 expression levels, extended these observations, demonstrating that C4 and D7 show comparable in vitro effector function against tumor lines with a range of IL13Ra2 expression levels.