HOXA9 and acute myeloid leukemia: Since MEIS1 levels are frequently elevated in normal karyotype AML (CN-AML), we used the murine Hoxa9/Meis1 AML model as a surrogate for CN-AML and performed Meis1 ChIP-seq analysis where we overexpressed HA-tagged wildtype Meis1 or an HA-tagged DNA binding mutant Meis1 (deltaHD-Meis1) with Hoxa9 [21, 30].