Essential transcriptional regulator necessary for development and differentiation of erythroid and megakaryocytic lineages. Alters histone methylation by recruiting histone methyltransferase to target genes promoters. Plays a role in heterochromatin formation. Expressed in erythroid cells of primitive and definitive lineage and bone marrow cells. The zinc finger domain is essential for erythroid expansion and acts as an activation domain whereas non finger domain serves as repression domain.