HOXA9 and leukemia: RNA-seq data collected from SEM cells in our previous studies suggested that HOXA7, HOXA9 and HOXA10 were the only highly expressed HOXA genes in MLLr leukemia SEM cells (Hyle et al., 2019; Figure 1E), and that these patterns were indistinguishable between WT and KI populations, indicating the P2A-mCherry knock-in did not alter the gene expression landscape at the HOXA cluster (Figure 1F).