ERBB2 and medulloblastoma: developed HER2‐CAR T cells containing the 4D5 single chain variable fragment (scFv) specific for HER2, CD3 zeta signaling domain and 4‐1BB costimulatory motif, referring to as HER2‐BBz‐CAR T cells, to combat medulloblastoma.[127] They found that intravenous administration of HER2‐BBz‐CAR T cells at high cell dose (2.5 × 106) could produce a complete regression of medulloblastoma cells in mice.