IL13RA2 and neoplasm: Each of the IL13(E12Y)-CAR T cell variants were also able to efficiently kill IL13Rα2-expressing tumor cells in a 48-hour coculture at E:T ratios of 1:4 (Fig. 1E), although the third-generation IL13-28BBζ CAR displayed slightly reduced killing potency against the GBM line PBT030-2.