PBX1 and acute myeloid leukemia: In poor prognosis (includes decreased overall survival, disease free survival, or response to therapy) AML, our comparison showed increased expression of several HOX/TALE genes, specifically HOXA4, HOXA10, HOXB5 and PBX1, while showing decreased expression of MEIS1 and contradictory expression directions of HOXB2 and PBX3. Although an overall increase of HOX/TALE expression in poor prognosis AML has been reported, there are several contradictions to this including MEIS1, HOXB2 and PBX3 in our comparison and HOXA4 in an outside RT-PCR study[60].