CD4 and acute lymphoblastic leukemia: The fifth cohort of recipient BALB/c mice was given 10 × 106 1 TCDBM cells along with 5 × 106 CD4+ and 5 × 106 CD8+ T cells from WT C57BL/6 mice, and these recipient mice were challenged with 2 × 105 B‐ALL‐luc cells (group 5).