Bivalent promoter methylation states in hematopoietic stem cells are evolutionarily conserved. (A) Venn diagram showing the conservation between promoters occupied with bivalent states in mouse and human HSCs. The human bivalent dataset was taken from a recent study describing chromatin modification profiles of CD133⁺ HSCs/HPCs.¹⁷  (B) Distribution of shared mouse and human bivalent promoters in different gene ontology categories.