(A) Bone marrow smear from a mouse 8 weeks after injection with cells from a patient with AML M4Eo showing the characteristic morphology of this subtype, including dysplastic eosinophils (black arrowhead) and leukemic blasts (white arrowheads). (B) FISH on a colony grown from the marrow of a mouse 8 weeks after injection with cells from pt 8. The probe used was D8Z2, which is specific for centromeric repeat sequences on human chromosome 8. The +8 abnormality previously identified in the leukemic clone of this patient is illustrated.