Homeobox genes, of which the most well-characterized category is represented by the HOX genes, play a crucial role in normal development. In addition, several homeoproteins are involved in neoplasia. This gene encodes a homeobox protein belonging to the TALE (three amino acid loop extension) family of homeodomain-containing proteins. [provided by RefSeq, Jul 2008],function:Acts as a transcriptional regulator of PAX6. Acts as a transcriptional activator of PF4 in complex with PBX1 or PBX2. Required for hematopoiesis, megakaryocyte lineage development and vascular patterning. May function as a cofactor for HOXA7 and HOXA9 in the induction of myeloid leukemias.,similarity:Belongs to the TALE/MEIS homeobox family.,similarity:Contains 1 homeobox DNA-binding domain.,subunit:Interacts with the N-terminal region of PBX1 to form a heterodimer which binds DNA including a cAMP-responsive sequence in CYP17. Also forms heterodimers with PBX2. Forms heterotrimers with PBX1 or PBX2 and a number of HOX proteins including HOXA9, HOXD4 and HOXD9 where it acts as a non-DNA-binding partner. Also forms heterotrimers with PBX1 and HOX proteins including HOXD9 and HOXD10 where PBX1 is the non-DNA-binding partner.,tissue specificity:Expressed at low level in normal immunohepatopoietic tissues, including the fetal liver. Expressed in a subset of myeloid leukemia cell lines, with the highest expression seen in those with a megakaryocytic-erythroid phenotype. Also expressed at high levels in the cerebellum.,
