Immunohistochemical staining showed that the expression levels of collagen I, collagen III and TGF-β in the DCM group were higher than those in the Control group, while the expression levels of these proteins in the Ad-PRR group were higher than those in the Ad-EGFP group, but there was no statistical significance between the DCM group and Ad-EGFP group (Figures 4A–C). Here, TGFB1 is linked to familial dilated cardiomyopathy.