MUC1 and acute myeloid leukemia: The oncogenic MUC1‐C subunit drives critical hallmarks of malignant cells, including cell proliferation, resistance to apoptosis, self‐renewal, and tissue invasion.3, 4, 5, 6 Intriguingly, we have demonstrated that MUC1 is uniquely expressed by AML stem cells as compared to normal haematopoietic stem cells.7 Primary AML cells expressing high levels of MUC1 efficiently induce leukaemic engraftment in a xenogeneic murine model, whereas MUC1 low expressing cells isolated from bone marrow of patients with active AML engraft normal haematopoietic elements.