Poor prognosis of a subtype of this disease and its potential precursors are linked to a deletion in chromosome 7’s long arm that manifests as a monosomy. Like its MPN and MDS precursors, a subtype of this disease may present with cytoplasmic granules and needle-like Auer rods. A chemotherapeutic 7+3 (“seven plus three”) regimen can treat a subtype of this disease, another subtype of which is treated by orally administering 6MP and methotrexate as part of its maintenance therapy. Imatinib treats a form of this disease by inhibiting a (*) BCR-ABL fusion protein originating from the Philadelphia chromosome. Subtypes of this disease can be described as acute or chronic and myeloid or lymphocytic. An abnormally (-5[1])high white blood cell count (-5[1])characterizes the chronic form of this disease. For 10 points, name this most common pediatric cancer that, like myelomas and lymphomas, may require a bone marrow transplant. (10[2])■END■