Cardiac fibrosis was also assessed by gene expression analysis of PAI-1 (Figure 4A; hDDAH1 hyper- vs. normotensive, 4.8 fold increase; WT hyper- vs. normotensive, 12.5 fold increase; each p<0.01), fibronectin (hDDAH1 hyper- vs. normotensive, 14.9 fold increase; p<0.05; WT hyper- vs. normotensive, 7.7 fold increase; p<0.01), and collagen III (hDDAH1 hyper- vs. normotensive, 4.1 fold increase; WT hyper- vs. normotensive, 3.7 fold increase; each p<0.01). This evidence concerns the gene FN1 and fibrosis.