Evolutionary conservation of human versus mouse gene expression in various hematopoietic cell types. (A) Schematic representation of overlap in differential gene expression between human and mouse. The percentage of maximum possible overlap, shown in parentheses, is the percentage of orthologous proteins of the lower number (human or mouse) of DE genes. For the 7 cell types with data in both human and mouse, the extent of conservation of differential gene expression is shown at the level of (B) all transcripts and (C) transcription factors only. For those genes that were detected as expressed in human blood cells, mouse orthologs were identified as described. The presence of these orthologs in the mouse data was then investigated. Venn diagrams showing the number of overlapping genes with the number of orthologs identified shown in parentheses.