CD19 and acute lymphoblastic leukemia: A sum of 3 × 106 of IL‐2‐expanded BT‐ or FTVII‐treated CD19‐CAR T cells from different donors were i.v. infused in NSG mice 3, 7, or 14 days after transplantation of Luc‐expressing NALM6 (Figure 3A), SEM (Figure 3B), or B‐ALL PDX (n = 2, Figure 4A), respectively.