The pathogenesis of cardiac fibrosis in DCM is complex, involving TGF-β, the renin-angiotensin-aldosterone system (RAAS), endothelin (ET), NO, vascular growth factor (VGF), Ca2+, and tissue inhibitors of metalloproteinases (TIMPs) (27). The gene discussed is TGFB1; the disease is familial dilated cardiomyopathy.