TGFB1 and Myocardial fibrosis: In the present study, (P)RR gene delivery in the normal adult heart induced deleterious myocardial fibrosis associated with the increased gene expression of TGFβ1 and CTGF as well as collagen Iα1, PAI-1 and fibronectin-1 indicating that (P)RR plays a critical role in hearts undergoing fibrotic remodeling process.