Gene expression profile analysis of biopsies from adult DM patients showed that mRNA levels of the genes that participate in endothelial adhesion (e.g., cathepsin B (CTSB), Endo 1-associated antigen (CD146)), proliferation (e.g., cyclin D1), differentiation (e.g., jagged protein), migration (e.g., hepatocyte growth factor), and activation (e.g., inositol 1,4,5 trisphosphate receptor type 1 (ITPR1), hypoxia-inducible factor 1 alpha subunit (HIF1A), toll-like receptor 3, and angiogenic inducer 61) are up-regulated in DM patients compared to controls. The gene discussed is CTSB; the disease is dermatomyositis.