Expression pattern of HOTAIRM1 during myelopoiesis. HG_U133 transcription profiles of the human HOXA cluster region were assembled for human hematopoietic stem/progenitor cells (HSPC), primary leukocytes, and myeloid cell line NB4. The stem/progenitor cell subpopulations are labeled according to the presence (+) or absence (−) of lineage development markers (CD33, CD34, CD38, or Lin) and low or high rhodamine 123 retention (Rh^low, Rh^high). Also indicated are the sources of the stem/progenitor cells: bone marrow (BM), cord blood (CB), fetal blood (FB), and G-CSF–mobilized peripheral blood (MPB). NB4 cells were examined either without treatment or after incubation with ATRA and TPA, as indicated. Primary leukocyte populations included total monocytes (MCs), adherent monocytes, monocyte-derived dendritic cells (DCs), resting neutrophils (PMNs), and neutrophils incubated with lipopolysaccharide (10 ng/mL) for 30 or 120 minutes, as indicated. The bar plot presents means and SDs for HOTAIRM1 and HOXA1 transcript levels in each sample group.