ERBB2 and glioblastoma: In a murine GBM model, tandem CAR T cells targeting HER2 and IL13Rα (two specific antigen targeting domains within one CAR construct) displayed enhanced activation and anti-tumor function without being more exhaustible than co-expressed HER2 and IL13Rα CAR T cells (biCAR T cells) or pool of single antigen HER2 or IL13Rα CAR T cells (49) (Figure 3).