HOXA9 and leukemia: We observed that in Hoxa9/IRX3 versus Hoxa9/MTV AML cells, there was significant enrichment of expression of the transcriptional sub-program that contributes to blocked differentiation and enhanced self-renewal of leukemia stem cells (LSCs) in murine MLL leukemias (LSC maintenance program; Somervaille et al., 2009) (Figure 5C; Tables S6 and S7).