Optimal immunotherapy target antigens are leukemia-specific antigens that are exclusively expressed by leukemia cells, are absent in normal tissues, and can elicit potent immune responses; however, with the exception of the BCR-ABL and PML-RARα fusion proteins, such leukemia-specific antigens are rare in other myeloid leukemias. This evidence concerns the gene ABL1 and myeloid leukemia.