The following extracellular matrix protein genes were up-regulated in DCM patients: MYOC (myocilin; 7.5-fold), FMOD (fibromodulin; 3.8-fold), OGN (osteoglycin; 3.0-fold), and SOD3 (extracellular superoxide dismutase [Cu-Zn]; 1.5-fold). The gene discussed is SOD3; the disease is familial dilated cardiomyopathy.