Lethally irradiated BALB/c mice were injected intravenously with 10 × 106 wild-type (WT) TCDBM cells along with 2 × 106 FACS-sorted donor T cells (1 × 106 CD8+ and 1 × 106 CD4+), followed by intravenous challenge with 2 × 105 luciferase-expressing B-ALL-luc blast cells as described (16). The gene discussed is CD4; the disease is acute lymphoblastic leukemia.