In contrast, the sixth cohort of recipient BALB/c mice was transplanted with 10 × 106 bone marrow cells, 0.5 × 106 CD8+ T cells and 0.5 × 106 CD4+ from ITK‐deficient mice in B6 background, and 2 × 105 B‐ALL‐luc cells (group 6). The gene discussed is CD4; the disease is acute lymphoblastic leukemia.