Immunohistochemical analysis of myocardial biopsies obtained from patients with heart failure due to dilated cardiomyopathy demonstrated increased OPN expression in cardiac myocytes, which correlated positively with impaired left ventricle (LV) function (Stawowy et al., 2002), and collagen type I levels (Satoh et al., 2005). This evidence concerns the gene SPP1 and heart failure.