While the role of the paired-type homeobox transcription factor MIXL1 in early embryonic development has been previously established, very little is known about the role of MIXL1 in adult hematopoiesis. To determine what role MIXL1 plays in adult hematopoietic cells, we established an enforced expression model for MIXL1 in the cell line U937, then analyzed the changes of gene expression caused by increased expression of MIXL1 by microarray analysis. Overall design: In attempt to identify the downstream role of MIXL1 in adult hematopoietic cells, we used previously established MIXL1 overexpression line (HL004-MIXL) and empty vector control (HL003-Vec) clones of the AML cell line U937. Both cell lines were grown for 24 hours at a starting concentration of 5x10^4/ml in 90% RMPI/10% FBS before being harvested for RNA. The RNA was then compared by microarray analysis, with the empty vector control sample (HL003-Vec) used as a control sample for the purposes of analysis.