Members of the angiogenic, anti-angiogenic, lymphocyte trafficking and complement activation pathways are highly up-regulated in DM patients compared to normal human muscle (NHM) controls. Gene-expression profiles generated from disease and control groups were analyzed using high-density oligonucleotide arrays. Gene expression values were obtained following Affymetrix MAS5 normalization. Manually grouped genes were further clustered with GeneSpring to visualize clusters of genes with similar expression pattern. Gene tree was colored by the expression of average over the whole group. Gene function was based on information available in public databases or in the literature.