Gene expression analysis of adult DM samples clearly showed that both PECAM1 and tissue factor are highly upregulated in these patients as are several dendritic cell/macrophage maturation markers (FLT3 ligand, CD68, CD11B, DC-LAMP, HLA-DQ, HLA-DRB, and B7-2) (data not shown). The gene discussed is HLA-DRB1; the disease is dermatomyositis.