Approximately 60%of cases of T-cell acute lymphoblastic leukemia (T-ALL) are characterized by an abnormally highlevel of TAL1 expression [9].Mutant forms of TAL1 in lymphoid and myeloid leukemia cellsare diagnosed in 20% of patients [10].The promoter portion of the C-KIT gene encoding the receptortyrosine kinase is considered as one of the main TAL1 targets in malignantblood cells. The gene discussed is TAL1; the disease is myeloid leukemia.