Background Hematopoietic stem cells (HSCs) are capable of differentiating into a number of divergent narrowly defined lineages that each give rise to a specific type of blood cell.In HSCs,a variety of lineage-specific transcription factors (TFs) and a large number of tissue non-specific TFs and cofactors are expressed.These TFs tend to interact with other TFs and/or cofactors to co-regulate specific gene expression programs instead of acting independently.