FN1 and Myocardial fibrosis: TGFβ1, a potent fibrogenic cytokine, plays an important role in the synthesis of collagen, fibronectin, or other intercellular substances, which leads to enhanced expression levels of collagen type I. Much evidence suggests that TGFβ1 overexpression is a common pathway for various pathological factors that cause myocardial fibrosis.