These results can be extended beyond regulation of mESC, as HOXA6 plays an important role in the regulation of HSC self-renewal in human, and its overexpression is also involved in leukemia [119]; HOXA7 acts as an intermediate in the regulation of granulocytic differentiation repressed by the Polycomb group RING finger protein 2 (PCGF2) [120]. Here, PCGF2 is linked to leukemia.