ERBB2 and precursor B-cell acute lymphoblastic leukemia: HER2 was amplified within a Myelodysplastic Syndrome (MDS) patient who developed AML6 and Herceptin, which targets the HER2 cell-surface receptor, also showed efficacy in refractory/relapsed HER2-positive adult B-acute lymphoblastic leukemia (B-ALL) patients7, 8.