Liu et al. transduced cord blood-derived NK cells with a retroviral vector incorporating the genes for CAR-CD19, IL-15, and inducible caspase-9-based suicide gene (Ic9), and it demonstrated efficient killing of CD19-expressing cell lines and primary leukemia cells in vitro, with dramatic prolongation of survival in a xenograft Raji lymphoma murine model [51]. This evidence concerns the gene CD19 and leukemia.