Cross-species comparison reveals extensive gene conservation between the species. Outcomes from ordered list algorithm are plotted, with each mRNA pool from 1 hybridization experiment depicted as 1 colored square, with high expression in yellow and low in blue. (A) The number of genes detected by the ordered list algorithm to be up-regulated in common when comparing human CD16⁻ or CD16⁺ monocytes with mouse Ly-6C⁺ or Ly-6C^lo monocytes. The 2 monocyte subset populations compared are shown on the x-axis under each bar graph. (B) Human and mouse gene lists are arranged to reveal matches of 79 of 132 genes between the species relative to the proposed counterparts of monocyte subsets in the 2 species. Heat map was truncated for simplicity. The entire heat map is presented as supplemental Figure 1 (available on the Blood website; see the Supplemental Materials link at the top of the online article). Data are shown in order of relative differences in gene expression profiles. (C) This panel depicts the 33 probe sets that were identified to be expressed in a pattern converse to the proposed analogy between monocyte subsets.