CD34 and acute myeloid leukemia: Bradbury et al. [113] explored HDAC9 expression in primary AML blasts and compared their results to HDAC9 levels in four other cell types, including quiescent or cycling CD34+ progenitor cells from umbilical cord blood and cycling CD34+ progenitors taken from peripheral mononuclear cells that were harvested from granulocyte colony-stimulating factor (GCSF)-stimulated adult donors.