MEIS1 and acute myeloid leukemia: Previous studies with patient samples have identified an inverse relationship between HOXA and HOXB cluster genes and MEIS1 compared to MN1.38 However, upregulation of HOXA9 also correlates to high MN1 expression in AML patients with complex karyotype/loss of chromosome 5 or 7.39 As upregulation of MEIS2 was recently reported in the context of patients with the RUNX1-RUNX1T1 translocation,11 we were interested in further assessing relationships between MEIS1, MEIS2 and MN1.