TGF-β1 and ECM production is upregulated following cardiac infarction in rats. Exogenous TGF-β1 can drive myocardial fibrosis in vivo. Cardiac fibroblasts differentiate into myofibroblasts in the presence of TGF-β1 (summarized in Lijnen et al., 2000). Here, TGFB1 is linked to Myocardial fibrosis.