Human and mouse monocyte subset arrays reveal some divergence from conservation. Bar graphs summarize the top 20 most differentially expressed genes between (A) human (■) and (B) mouse (□) monocyte subsets. Results are depicted as relative fold change, as determined by microarray, where negative values are more highly expressed on the CD16⁻ human or Ly-6C⁺ mouse monocyte subset and positive values are more highly expressed on the CD16⁺ human or Ly-6C^lo mouse subset.