When ATA μκTg generation in mice, ATA B cells are the neonate generated CD5+ B cells in B-1, and in the middle age, CD5+ can be down or continuously CD5+, then, old aged CLL/lymphoma generation with increased CD11b in TC–ZAP70–CD5– or TC–ZAP70+CD5+. The gene discussed is CD5; the disease is B-cell chronic lymphocytic leukemia.